Abstracts of the CMS PRESS PUBLICATIONS



PRINCIPLES AND PRACTICE OF EVACUATION MODELLING A COLLECTION OF LECTURE NOTES FOR A SHORT COURSE.

Prof Ed Galea
Director Fire Safety Engineering Group
Course Co-ordinator.

PREFACE.

The ability to enable efficient circulation of people in heavily populated enclosures is important to the day to day operation of large commercial buildings such as airport terminals, railway and underground stations, shopping malls and cinemas. More importantly, it is an essential design feature in the event of emergency situations.

As architects continue to implement novel concepts in building design, they are increasingly finding that the fixed criteria of the traditional methods of prescriptive building codes are too restrictive. This is due in part to their almost total reliance on configurational considerations such as travel-distance and exit width. Furthermore, as these traditional prescriptive methods are insensitive to human behaviour or likely fire scenarios, it is unclear if they indeed offer the optimal solution in terms of evacuation efficiency.

The emergence of performance based building codes together with computer based evacuation models offer the potential of overcoming these shortfalls and addressing the needs not only of the designers but also the legislators. However, if such models are to make a useful contribution they must address the configurational, environmental, behavioural and procedural aspects of the evacuation process.

Over the past 15 years a variety of different modelling methodologies have been developed by which to represent the evacuation process. Furthermore, within these various modelling methodologies, there are also a number of ways in which to represent the enclosure, population and the behaviour of the population. The myriad approaches which are available has led to the development of some 22 different evacuation models which are currently available. However, while the modelling tools have proliferated, there has not been a corresponding transfer of knowledge and understanding of the discipline from the model developer to the general user. It is a serious shortfall of which the lack of suitable engineering courses dealing with the subject is symptomatic, if not the cause.

Simply possessing a computer to run the models is not enough to exploit these sophisticated tools. They can too easily become 'black boxes' producing magic answers in exciting colour graphics and client-satisfying 'virtual reality' imagery. As well as a fundamental understanding of the range of human psychological and physiological responses to fire, the fire safety engineer must have at least a rudimentary understanding of the theoretical basis supporting evacuation models to appreciate their limitations and capabilities.

The five day short course, "Principles and Practice of Evacuation Modelling" run by the University of Greenwich attempt to bridge the divide between the model developer and the general user, providing them with the expertise they need to understand evacuation modelling. These concepts and techniques are introduced and demonstrated in a series of seminars. Those attending also gain experience in using the methods during "hands-on" tutorial and workshop sessions.

On completion of this short course, those participating should:

- be familiar with the range of human psychological and physiological responses to fire;

- be familiar with evacuation model assumptions;

- have an understanding of the capabilities and limitations of evacuation modelling software;

- be able to use egress software to assess the evacuation performance of a structure under fire conditions;

- be able to interpret model predictions.

The result is that the fire safety engineer is empowered to realise the full value of mathematical models to help in the prediction of human behaviour during evacuation, and to determine the consequences of fire under a variety of conditions. This in turn enables them to design and implement safety measures which can potentially control, or at the very least reduce the impact of fire.

The contents of this course are based on the work of the FSEG EXODUS Development Group which consists of Prof E Galea, Dr P Lawrence, Mr M Owen, Mr L Filippidis and Mr S Gwynne. Prof Galea and Mr Owen are indepted to the members of the group for their invaluable assistance in developing the lecture and tutorial material. In particular, the lecture material draws on a number of publications produced jointly by all the members of the group.




VALIDATION OF EVACUATION MODELS.

Prof Ed Galea

ABSTRACT:

Too often, validation of computer models is considered as a "once and forget" task. In this paper a systematic and graduated approach to evacuation model validation is suggested. This involves,

(i) component testing,

(ii) functional validation,

(iii) qualitative validation and

(iv) quantitative validation.

Viewed in this manner, validation is considered an on-going activity and an integral part of the life cycle of the software. While the first three components of the validation protocol pose little or no significant problems, the task of quantitative validation poses a number of challenges, the most significant being a shortage of suitable experimental data. Finally, the validation protocol used in the development of the EXODUS suite of evacuation models is examined.



A REVIEW OF THE METHODOLOGIES AND CRITICAL APPRAISAL OF COMPUTER MODELS USED IN THE SIMULATION OF EVACUATION FROM THE BUILT ENVIRONMENT.

S.Gwynne and E. R. Galea.

1.0 Abstract.

Computer based analysis of evacuation can be performed using one of three different approaches, namely optimisation, simulation and risk assessment. Furthermore, within each approach different means of representing the enclosure, the population and the behaviour of the population are possible. The myriad of approaches which are available has led to the development of some 22 different evacuation models. This review attempts to describe each of the modelling approaches and critically review the capabilities of each model in light of the adopted approach. The review is based on available published literature.



ADVANCED OCCUPANT BEHAVIOURAL FEATURES OF THE building-EXODUS EVACUATION MODEL

M. Owen, E. R. Galea and P. Lawrence

ABSTRACT

The purpose of this paper is to describe and demonstrate some of the advanced behavioural features currently being developed for the building-EXODUS evacuation model. These advanced features involve the ability to specify roles for particular individuals during the evacuation. With these enhancements to the Behavioural Submodel of building-EXODUS, it is possible to include a number of procedural and behavioural aspects previously ignored in evacuation simulations. These include the behavioural aspect of group bonding, the procedural aspects involved with the role of the fire warden and rescue operations undertaken by the fire services. The importance of these enhancements are discussed and demonstrated through three simple simulations.

KEYWORDS: evacuation, computer model, human behaviour, rescue, fire warden, group bonding.



SMARTFIRE: AN INTEGRATED COMPUTATIONAL FLUID DYNAMICS CODE AND EXPERT SYSTEM FOR FIRE FIELD MODELLING.

S. Taylor¨ , E.R.Galea*, M. Patel*, M. Petridis¨ , B. Knight¨ , J. Ewer¨ .

ABSTRACT

SMARTFIRE, an open architecture integrated CFD code and knowledge based system attempts to make fire field modelling accessible to non-experts in Computational Fluid Dynamics (CFD) such as fire fighters, architects and fire safety engineers. This is achieved by embedding expert knowledge into CFD software. This enables the 'black-art' associated with the CFD analysis such as selection of solvers, relaxation parameters, convergence criteria, time steps, grid and boundary condition specification to be guided by expert advice from the software. The user is however given the option of overriding these decisions, thus retaining ultimate control. SMARTFIRE also makes use of recent developments in CFD technology such as unstructured meshes and group solvers in order to make the CFD analysis more efficient. This paper describes the incorporation within SMARTFIRE of the expert fire modelling knowledge required for automatic problem setup and mesh generation as well as the concept and use of group solvers for automatic and manual dynamic control of the CFD code.

KEYWORDS: fire modelling, field modelling, CFD, expert system, artificial intelligence



ON THE MODELLING OF FIRE ATMOSPHERE / SPRINKLER SPRAY INTERACTIONS USING AN EULER - LAGRANGE FRAMEWORK

R.N.Mawhinney, E.R.Galea and M.K.Patel

ABSTRACT

An Euler-Lagrange particle tracking model, developed for simulating fire atmosphere/sprinkler spray interactions, is described. Full details of the model along with the approximations made and restrictions applying are presented. Errors commonly found in previous formulations of the source terms used in this two-phase approach are described and corrected. In order to demonstrate the capabilities of the model it is applied to the simulation of a fire in a long corridor containing a sprinkler. The simulation presented is three-dimensional and transient and considers mass, momentum and energy transfer between the gaseous atmosphere and injected liquid droplets.

KEYWORDS: fire modelling, field modelling, CFD, two-phase flow, sprinkler, spray.



The Prediction of Fire Propagation in Enclosure Fires

F. Jia, E.R. Galea and M.K. Patel

ABSTRACT

In this paper we present some early work concerned with the development of a simple solid fuel combustion model incorporated within a Computational Fluid Dynamics (CFD) framework. The model is intended for use in engineering applications of fire field modelling and represents an extension of this technique to situations involving the combustion of solid cellulosic fuels. A simple solid fuel combustion model consisting of a thermal pyrolysis model, a six flux radiation model and an eddy-dissipation model for gaseous combustion have been developed and implemented within the CFD code CFDS-FLOW3D. The model is briefly described and demonstrated through two applications involving fire spread in a compartment with a plywood lined ceiling. The two scenarios considered involve a fire in an open and closed compartment. The model is shown to be able to qualitatively predict behaviours similar to flashover - in the case of the open room - and backdraft - in the case of the initially closed room.

KEYWORDS: CFD, field model, pyrolysis, solid fuel combustion, flashover, backdraft



A Two-Dimensional Numerical Simulation of the Oscillatory Flow Behaviour in Fire Compartments with a Single Horizontal Ceiling Vent

L. Kerrison, E. R. Galea and M. K. Patel

ABSTRACT

This paper presents a comparison of fire field model predictions with experiment for the case of a fire within a compartment which is vented (buoyancy-driven) to the outside by a single horizontal ceiling vent. Unlike previous work, the mathematical model does not employ a mixing ratio to represent vent temperatures but allows the model to predict vent temperatures a priori. The experiment suggests that the flow through the vent produces oscillatory behaviour in vent temperatures with puffs of smoke emerging from the fire compartment. This type of flow is also predicted by the fire field model. While the numerical predictions are in good qualitative agreement with observations, they over predict the amplitudes of the temperature oscillations within the vent and the compartment temperatures. The discrepancies are thought to be due to three-dimensional effects not accounted for in this model. The numerical results also suggest that a linear relationship exists between the frequency of vent temperature oscillation (n) and the heat release rate (Q0) of the type n µQ00.29, similar to that observed for compartments with two horizontal vents. This relationship is predicted to occur only for heat release rates below a critical value. Furthermore, the vent discharge coefficient is found to vary in an oscillatory fashion with a mean value of 0.58. Below the critical heat release rate the mean discharge coefficient is found to be insensitive to fire size.



A COLLECTION OF PAPERS PRESENTED BY THE FIRE SAFETY ENGINEERING GROUP AT THE FIRST EUROPEAN SYMPOSIUM ON FIRE SAFETY SCIENCE ZURICH 21-23 AUGUST 1995

COLLATED BY PROFESSOR E. R. GALEA

PREFACE

The First European Symposium on Fire Safety Science was held at the Institute for Structural Engineering of ETH in Zurich from 21st - 23rd August 1995. The Fire Safety Engineering Group (FSEG) of the University of Greenwich made six presentations at the symposium, three papers and three posters. This document is a collection of that work and consists of the extended abstracts and the view graphs for each paper and a copy of each poster. The work presented represents only a portion of the fire research activity at the University of Greenwich. For more information concerning our activities please contact Prof. Ed Galea at the University of Greenwich.



COLLECTION OF PAPERS PRESENTED BY THE FIRE SAFETY ENGINEERING GROUP AT THE INTERFLAM96 CONFERENCE CAMBRIDGE, 26-28 MARCH 1996

COLLATED BY PROFESSOR E. R. GALEA

PREFACE

NTERFLAM 96 was held at St John's College, Cambridge from 26 to 28 March 1996. The Fire Safety Engineering Group (FSEG) of the University of Greenwich made four presentations at the symposium, two papers and two posters. This document is a collection of that work and consists of a copy of each paper and poster. The work presented represents only a portion of the fire research activity at the University of Greenwich. For more information concerning our activities please contact Prof. Ed Galea at the University of Greenwich.

The full conference proceedings may be obtained from Interscience Communications.



COMBUSTION MODELS OF TURBULENT DIFFUSION FLAMES

F. Jia, E. Galea, M. Patel and N. Hoffmann

Abstract

In the present paper, the basic features of turbulent diffusion flames are described. Four widely used combustion models are discussed. Two kinds of mathematical models implemented on FLOW3D (version 2.3.3) are established to simulate turbulent diffusion flames. One is the combustion model using the eddy dissipation concept. The other is the heat source model in which the flame is simulated as a simple source of heat. The comparison of the combustion model implemented on FLOW3D (version 2.3.3) with the combustion model included in CFDS-FLOW3D (version 3.3) shows in good agreement on the numerical solutions of the two models except at the flame sheet. It is guessed that the difference of the values at the flame sheet arises from the different linearization of the source term for mass fraction of fuel in the models. The heat source models predict the same flow trends far from the combustion region as the ones predicted by the combustion models.



On the Modelling of the Thermal Interactions Between a Spray Curtain and an Impinging Cold Gas Cloud

E. Alessandrν, J M Buchlin, A Cavallini, M K Patel and E Galea

ABSTRACT

A mixed Lagrangian-Eulerian model of a Water Curtain barrier is presented. The heat, mass and momentum processes are modelled in a Lagrangian framework for the dispersed phase and in an Eulerian framework for the carrier phase. The derivation of the coupling source terms is illustrated with reference to a given carrier phase cell. The turbulent character of the flow is treated with a single equation model, modified to directly account for the influence of the particles on the flow. The model is implemented in the form of a 2 D incompressible Navier Stokes solver, coupled to an adaptive Rung Kutta method for the Lagrangian sub-system. Simulations of a free standing full cone water spray show satisfactory agreement with experiment. Predictions of a Water Curtain barrier impacted by a cold gas cloud point to markedly different flow fields for the upward and downward configurations, which could influence the effectiveness of chemical absorption in the liquid phase.



NUMERICAL OPTIMISATION OF WATER CURTAIN BARRIERS DESIGN

E Alessandrν, J M Buchlin and M K Patel

Abstract

The interactions between water curtain protective barriers and impinging cold gas clouds released during industrial accidents are simulated by a 2D finite difference code using a PSI-cell of the heat, mass and momentum transfer processes between the phases. A consistent derivation of the continuous phase source terms is presented. The results of early simulations of an existing 1:10 experimental model of a water curtain impacted by a cold gas cloud are presented for two typical curtain configurations.



PRINCIPLES AND PRACTICE OF FIRE MODELLING A COLLECTION OF LECTURE NOTES FOR A SHORT COURSE

Prof Ed Galea
Director Fire Safety Engineering Group
Course Co-Ordinator.

PREFACE

Once the preserve of university academics and research laboratories with high-powered and expensive computers, the power of sophisticated mathematical fire models has now arrived on the desk top of the fire safety engineer. It is a revolution made possible by parallel advances in PC technology and fire modelling software. But while the tools have proliferated, there has not been a corresponding transfer of knowledge and understanding of the discipline from expert to general user. It is a serious shortfall of which the lack of suitable engineering courses dealing with the subject is symptomatic, if not the cause.

The computational vehicles to run the models and an understanding of fire dynamics are not enough to exploit these sophisticated tools. Too often, they become 'black boxes' producing magic answers in exciting three-dimensional colour graphics and client-satisfying 'virtual reality' imagery.

As well as a fundamental understanding of the physics and chemistry of fire, the fire safety engineer must have at least a rudimentary understanding of the theoretical basis supporting fire models to appreciate their limitations and capabilities. The five day short course, "Principles and Practice of Fire Modelling" run by the University of Greenwich attempt to bridge the divide between the expert and the general user, providing them with the expertise they need to understand the results of mathematical fire modelling. The course and associated text book, "Mathematical Modelling of Fire Phenomena" are aimed at students and professionals with a wide and varied background, they offer a friendly guide through the unfamiliar terrain of mathematical modelling.

These concepts and techniques are introduced and demonstrated in seminars. Those attending also gain experience in using the methods during "hands-on" tutorial and workshop sessions.

On completion of this short course, those participating should:

- be familiar with the concept of zone and field modelling;

- be familiar with zone and field model assumptions;

- have an understanding of the capabilities and limitations of modelling software packages for zone and field modelling;

- be able to select and use the most appropriate mathematical software and demonstrate their use in compartment fire applications; and

- be able to interpret model predictions.

The result is that the fire safety engineer is empowered to realise the full value of mathematical models to help in the prediction of fire development, and to determine the consequences of fire under a variety of conditions. This in turn enables him or her to design and implement safety measures which can potentially control, or at the very least reduce the impact of fire.



THE USE OF MATHEMATICAL MODELLING IN FIRE SAFETY ENGINEERING

Prof E.R.Galea
Fire Safety Engineering Group
Centre for Numerical Modelling and Process Analysis
University of Greenwich

Fire is a form of uncontrolled combustion which generates heat, smoke, toxic and irritant gases. All of these products are harmful to man and account for the heavy annual cost of 800 lives and £1,000,000,000 worth of property damage in Britain alone. The new discipline of Fire Safety Engineering has developed as a means of reducing these unacceptable losses. One of the main tools of Fire Safety Engineering is the mathematical model and over the past 15 years a number of mathematical models have emerged to cater for the needs of this discipline. Part of the difficulty faced by the Fire Safety Engineer is the selection of the most appropriate modelling tool to use for the job. To make an informed choice it is essential to have a good understanding of the various modelling approaches, their capabilities and limitations. In this paper some of the fundamental modelling tools used to predict fire and evacuation are investigated as are the issues associated with their use and recent developments in modelling technology.



Escape as a Social Response

Steve Gwynne, E.R.Galea, M.Owen, P.J.Lawrence
Fire Safety Engineering Group
Centre for Numerical Modelling and Process Analysis
University of Greenwich

This report examines occupant behaviour exhibited during evacuation conditions. This is based on a review of a wide range of published literature concerned with evacuation. Occupant response is identified as being due to a number of diverse factors relating to the enclosure configuration, enclosure environment and enclosure specific procedures. These include the effectiveness of the alarm system, the type of enclosure, the make-up of the population, the presence / absence of smoke, head and toxic gases, etc. These factors are then examined individually, to determine their frequency and importance. Finally, in light of this discussion, the factors necessary in the formation of a comprehensive behavioural model for evacuation are suggested.



Numerical Simulation of the Mass Loss Process in Pyrolizing Char Materials

F. Jia, E.R. Galea and M.K. Patel
Fire Safety Engineering Group
Centre for the Numerical Modelling and Process Analysis
University of Greenwich

We present here a decoupling technique to tackle the entanglement of the nonlinear boundary condition and the movement of the char/virgin front for a thermal pyrolysis model for charring materials. Standard numerical techniques to solve moving front problems - often referred to as Stefan problems - encounter difficulties when dealing with nonlinear boundaries. While special integral methods have been developed to solve this problem, they suffer from several limitations which the technique described here overcomes. The newly developed technique is compared with the exact analytical solutions for some simple ideal situations which demonstrate that the numerical method is capable of producing accurate numerical solutions. The pyrolysis model is also used to simulate the mass loss process from a white pine sample exposed to a constant radiative flux in a nitrogen atmosphere. Comparison with experimental results demonstrates that the predictions of mass loss rates and temperature profile within the solid material are in good agreement with the experiment.



THE NUMERICAL SIMULATION OF AIRCRAFT EVACUATION AND ITS APPLICATION TO AIRCRAFT DESIGN AND CERTIFICATION.

E.R. Galea, M.Owen, P.J.Lawrence and L Filippidis.
Fire Safety Engineering Group
University of Greenwich

Computer based mathematical models describing the aircraft evacuation process have a vital role to play in the design and development of safer aircraft, in the implementation of safer and more rigorous certification criteria and in cabin crew training and post mortuum accident investigation. As the risk of personal injury and costs involved in performing large-scale evacuation experiments for the next generation `Ultra High Capacity Aircraft' (UHCA) are expected to be high, the development and use of these evacuation modelling tools may become essential if these aircraft are to prove a viable reality. This paper describes the capabilities and limitations of the airEXODUS evacuation model and some attempts at validation, including its successful application to the prediction of a recent certification trial, prior to the actual trial taking place, is described. Also described is a newly defined parameter known as OPS which can be used as a measure of evacuation trial optimality. In addition, sample evacuation simulations in the presence of fire atmospheres are described. 



VALIDATION OF THE buildingEXODUS EVACUATION MODEL

S. Gwynne, E.R. Galea, M. Owen, P.J. Lawrence, L. Filippidis
Fire Safety Engineering Group
University of Greenwich

In this paper, the buildingEXODUS (V1.1) evacuation model is described and discussed and attempts at qualitative and quantitative model validation are presented. The data sets used for validation are the Stapelfeldt and Milburn House evacuation data. As part of the validation exercise, the sensitivity of the buildingEXODUS predictions to a range of variables is examined, including: occupant drive, occupant location, exit flow capacity, exit size, occupant response times and geometry definition. An important consideration that has been highlighted by this work is that any validation exercise must be scrutinised to identify both the results generated and the considerations and assumptions on which they are based. During the course of the validation exercise, both data sets were found to be less than ideal for the purpose of validating complex evacuation models. However, the buildingEXODUS evacuation model was found to be able to produce reasonable qualitative and quantitative agreement with the experimental data. 



SMARTFIRE: AN INTELLIGENT CFD BASED FIRE MODEL

S. Taylor, E.R. Galea, J. Ewer, M.K. Patel, M. Petridis, B. Knight
Fire Safety Engineering Group
University of Greenwich

This paper describes a project aimed at making Computational Fluid Dynamics (CFD) based fire simulation accessible to members of the fire safety engineering community. Over the past few years, the practise of CFD based fire simulation has begun the transition from the confines of the research laboratory to the desk of the fire safety engineer. To a certain extent, this move has been driven by the demands of performance based building codes. However, while CFD modelling has many benefits over other forms of fire simulation, it requires a great deal of expertise on the user’s part to obtain reasonable simulation results. The project described in this paper, SMARTFIRE, aims to relieve some of this dependence on expertise so that users are less concerned with the details of CFD analysis and can concentrate on results. This aim is achieved by the use of an expert system component as part of the software suite which takes some of the expertise burden away from the user. SMARTFIRE also makes use of the latest developments in CFD technology in order to make the CFD analysis more efficient. This paper describes design considerations of the SMARTFIRE software, emphasising its open architecture, CFD engine and knowledge based systems. 



FURTHER VALIDATION OF THE buildingEXODUS EVACUATION MODEL USING THE TSUKUBA DATASET

S. Gwynne, E.R. Galea, P.J. Lawrence, M. Owen, L. Filippidis
Fire Safety Engineering Group
University of Greenwich

In this paper, the buildingEXODUS (V1.1) evacuation model is described and discussed and attempts at qualitative and quantitative model validation are presented. The data set used for the validation is the Tsukuba pavilion evacuation data. This data set is of particular interest as the evacuation was influenced by external conditions, namely inclement weather. As part of the validation exercise, the sensitivity of the buildingEXODUS predictions to a range of variables and conditions is examined, including; exit flow capacity, occupant response times and the impact of external conditions on the developing evacuation. The buildingEXODUS evacuation model was found to be able to produce good qualitative and quantitative agreement with the experimental data. 



FIRE FIELD MODELLING USING THE SMARTFIRE AUTOMATED DYNAMIC SOLUTION CONTROL ENVIRONMENT

J. Ewer, E.R. Galea, B. Knight, M. Patel, D. Janes, M. Petridis
Fire Safety Engineering Group
University of Greenwich

SMARTFIRE is a fire field model based on an open architecture integrated CFD code and knowledge-based system. It makes use of the expert system to assist the user in setting up the problem specification and new computational techniques such as Group Solvers to reduce the computational effort involved in solving the equations. This paper concentrates on recent research into the use of artificial intelligence techniques to assist in dynamic solution control of fire scenarios being simulated using fire field modelling techniques. This is designed to improve the convergence capabilities of the software while further decreasing the computational overheads. The technique automatically controls solver relaxations using an integrated production rule engine with a blackboard to monitor and implement the required control changes during solution processing. Initial results for a two-dimensional fire simulation are presented that demonstrate the potential for considerable savings in simulation run-times when compared with control sets from various sources. Furthermore, the results demonstrate enhanced solution reliability due to obtaining acceptable convergence within each time step unlike some of the comparison simulations. 



ADAPTIVE DECISION-MAKING IN buildingEXODUS

S. Gwynne, E.R. Galea, P.J. Lawrence, M. Owen, L. Filippidis
Fire Safety Engineering Group
University of Greenwich

Given the importance of occupant behaviour on evacuation efficiency, a new behavioural feature has been implemented into buildingEXODUS. This feature concerns the response of occupants to exit selection and re-direction. This behaviour is not simply pre-determined by the user as part of the initialisation process, but involves the occupant taking decisions based on their previous experiences and the information available to them. This information concerns the occupants prior knowledge of the enclosure and line-of-sight information concerning queues at neighbouring exits. This new feature is demonstrated and reviewed through several examples. 



THE FIREDASS (FIRE DETECTION AND SUPPRESSION SIMULATION) MODEL

A. Grandison, R. Mawhinney, E. Galea, M. K. Patel, E. Keramida, A. Boudouvis, N. Markatos
Fire Safety Engineering Group
University of Greenwich

The FIREDASS (FIRE Detection And Suppression Simulation) project is concerned with the development of fine water mist systems as a possible replacement for the halon fire suppression system currently used in aircraft cargo holds. The project is funded by the European Commission, under the BRITE EURAM programme. The FIREDASS consortium is made up of a combination of Industrial, Academic, Research and Regulatory partners. As part of this programme of work, a computational model has been developed to help engineers optimise the design of the water mist suppression system. This computational model is based on Computational Fluid Dynamics (CFD) and is composed of the following components: fire model; mist model; two-phase radiation model; suppression model and detector/activation model. The fire model - developed by the University of Greenwich - uses prescribed release rates for heat and gaseous combustion products to represent the fire load. Typical release rates have been determined through experimentation conducted by SINTEF. The mist model - developed by the University of Greenwich - is a Lagrangian particle tracking procedure that is fully coupled to both the gas phase and the radiation field. The radiation model - developed by the National Technical University of Athens - is described using a six-flux radiation model. The suppression model - developed by SINTEF and the University of Greenwich - is based on an extinguishment crietrion that relies on oxygen concentration and temperature. The detector/ activation model - developed by Cerberus - allows the configuration of many different detector and mist configurations to be tested within the computational model. These sub-models have been integrated by the University of Greenwich into the FIREDASS software package. The model has been validated using data from the SINTEF/GEC test campaigns and it has been found that the computational model gives good agreement with these experimental results. The best agreement is obtained at the ceiling which is where the detectors and misting nozzles would be located in a real system. In this paper the model is briefly described and some results from the validation of the fire and mist model are presented. 




ENHANCING THE NUMERICAL PERFORMANCE OF FIRE FIELD MODELS.

J.A.C. Ewer, E.R. Galea, M.K. Patel,  B. Knight.
Fire Safety Engineering Group.
University of Greenwich,
http://fseg.gre.ac.uk

This paper describes two new techniques designed to enhance the performance of fire field modelling software. The two techniques are "group solvers" and automated dynamic control of the solution process, both of which are currently under development within the SMARTFIRE Computational Fluid Dynamics environment. The "group solver" is a derivation of common solver techniques used to obtain numerical solutions to the algebraic equations associated with fire field modelling. The purpose of "group solvers" is to reduce the computational overheads associated with traditional numerical solvers typically used in fire field modelling applications.  In an example, discussed in this paper, the group solver is shown to provide a 37% saving in computational time compared with a traditional solver. The second technique is the automated dynamic control of the solution process, which is achieved through the use of artificial intelligence techniques. This is designed to improve the convergence capabilities of the software while further decreasing the computational overheads. The technique automatically controls solver relaxation using an integrated production rule engine with a blackboard to monitor and implement the required control changes during solution processing. Initial results for a two-dimensional fire simulation are presented that demonstrate the potential for considerable savings in simulation run-times when compared with control sets from various sources. Furthermore, the results demonstrate the potential for enhanced solution reliability due to obtaining acceptable convergence within each time step, unlike some of the comparison simulations.




Simulating One of the CIB W14 Round Robin Test Cases Using the SMARTFIRE FIRE FIELD MODEL.

Z. Wang, F. Jia, E.R. Galea, M.K. Patel and J. Ewer.
Fire Safety Engineering Group.
University of Greenwich,
http://fseg.gre.ac.uk

Numerical predictions produced by the SMARTFIRE fire field model are compared with experimental data.  The predictions consist of gas temperatures at several locations within the compartment over a 60 minute period. The test fire, produced by a burning wood crib attained a maximum heat release rate of approximately 11 MW. The fire is intended to represent a non-spreading fire (i.e. single fuel source) in a moderately sized ventilated room.  The experimental data formed part of the CIB Round Robin test series.  Two simulations are produced, one involving a relatively coarse mesh and the other with a finer mesh.  While the SMARTFIRE simulations made use of a simple volumetric heat release rate model, both simulations were found capable of reproducing the overall qualitative results.  Both simulations tended to over-predict the measured temperatures. However, the finer mesh simulation was better able to reproduce the qualitative features of the experimental data. The maximum recorded experimental temperature (1214oC after 39 minutes) was over-predicted in the fine mesh simulations by 12%.



Modelling Occupant Interaction with Fire conditions Using The buildingEXODUS Evacuation Model

S. Gwynne, E.R. Galea, P.J. Lawrence, L. Filippidis
Fire Safety Engineering Group
University of Greenwich,
http://fseg.gre.ac.uk/

When evacuating through fire environments, the presence of smoke may not only have a physiological impact on the evacuees but may also lead occupants to adapt their evacuation strategy through the adoption of another exit.  This paper attempts to introduce this type of adaptive behaviour within the buildingEXODUS evacuation model through enabling occupants to make decisions concerning the selection of the most viable available exit during an evacuation involving fire.  The development of this adaptive behaviour requires the introduction of several new capabilities namely, the representation of the occupants familiarity with the structure, the behaviour of an occupant that is engulfed in smoke and the behaviour of an occupant that is faced with a smoke barrier.  The appropriateness of the redirection decision is dependent upon behavioural data gathered from real fire incidents (in the UK and USA) that is used to construct the redirection probabilities.  The implementation is shown to provide a more complex and arguably more realistic representation of this behaviour than that provided previously.



Evacuating an Overturned Smoke Filled Rail Carriage

GALEA, E.,R. AND GWYNNE, S.
FIRE SAFETY ENGINEERING GROUP
University of Greenwich,
http://fseg.gre.ac.uk/

Incidents requiring the rapid egress of passengers from trains are infrequent.  However, there is an obvious requirement to ensure that rail vehicle design and crew procedures are adequate to allow the safe egress of passengers under a variety of conditions.  Perhaps the most challenging scenario for passengers involves the evacuation from an overturned or partially overturned carriage resulting from a crash or derailment.  In the most severe cases, fire/smoke may also be present.  In this paper we investigate the evacuation of passengers from rail carriages with a focus on overturned carriages.  This is achieved through a study of passenger accounts from past accidents and two full-scale evacuation experiments involving an overturned carriage, in one of which the participants were subjected to non-toxic smoke.  The carriage used in the experiments is a standard class Mark IID, which while an old carriage design, shares many features with those carriages commonly found on the British rail network.  In the evacuation involving smoke, the carriage end exit was found to have an average flow rate capacity of approximately 5.0 persons/minute.  It is estimated that under such conditions, a full carriage load of 62 passengers would require approximately 13 minutes 19 seconds to evacuate through a single end exit.  Due to the conditions of the trial, this time is considered optimistic.  It is noted that the presence of smoke tends to almost half the exit flow rate and almost double the evacuation time.  Finally, from observations of the performance and behaviour of the evacuating passengers, a number of suggestions are made concerning carriage layout modifications designed to improve passenger survivability.



Using Computer Simulation to Predict the Evacuation Performance of  Passenger Ships

E Galea, S Gwynne, P Lawrence
Fire Safety Engineering Group
University of Greenwich
London SE10 9LS, UK

 

When designing a new passenger ship or modifying an existing design, how do we ensure that the proposed design is safe from an evacuation point of view? In the building and aviation industries, computer based evacuation models are being used to tackle similar issues. In these industries the traditional restrictive prescriptive approach to design is making way for performance based design methodologies using risk assessment and computer simulation. In the maritime industry, ship evacuation models offer the promise to quickly and efficiently bring these considerations into the design phase, while the ship is “on the drawing board”. This paper describes the development of evacuation models with applications to passenger ships and further discusses issues concerning data requirements and validation.



The Development of a CFD Based Simulator for Water Mist Fire Suppression Systems: The Development of the Fire Submodel

R Mawhinney, A Grandison, E Galea, M Patel
Fire Safety Engineering Group
University of Greenwich
London SE10 9LS, UK

 

The FIREDASS (FIRE Detection And Suppression Simulation) project was concerned with the development of water misting systems as a possible replacement for halon based fire suppression systems currently used in aircraft cargo holds and ship engine rooms. As part of this programme of work, a computational model was developed to assist engineers optimise the design of water mist suppression systems. The model is based on Computational Fluid Dynamics (CFD) and comprised of the following components: fire model; mist model; two-phase radiation model; suppression model; detector/activation model. In this paper the FIREDASS software package is described and the theory behind the fire and radiation submodels is detailed. The fire model uses prescribes release rates for heat and gaseous combustion products to represent the fire load. Typical release rates have been determined through experimentation. The radiation model is a six-flux model coupled to the gas (and mist) phase. As part of the FIREDASS project, a detailed series of fire experiments were conducted in order to validate the fire model. Model predictions are compared with data from these experiments and good agreement is found.



Examining the Effect of Exit Separation on Aircraft Evacuation Performance using Evacuation Modelling Techniques: “Is the 60 Foot Rule Relevant?” 

S Blake, E Galea, S Gwynne, P Lawrence, L Filippidis
Fire Safety Engineering Group
University of Greenwich
London SE10 9LS, UK

 

This paper examines the influence of exit separation, exit availability and seating configuration on aircraft evacuation efficiency and evacuation time. The purpose of this analysis is to explore how these parameters influence the 60 foot exit separation requirement found in aircraft certification rules. The analysis makes use of the airEXODUS evacuation model and is based on a typical wide-body aircraft cabin section involving two pairs of Type-A exits located at either end of the section with a maximum permissible loading of 220 passengers located between the exits. The analysis reveals that there is a complex relationship between exit separation and evacuation efficiency. Indeed, other factors such as exit flow rate and exit availability are shown to exert a strong influence on critical exit separations. A main finding of this work is that for the cabin section examined under certification conditions, exit separations up to 170 feet will result in approximately constant total evacuation times and average personal evacuation times. This practical exit separation threshold is decreased to 114 feet if another combination of exits is selected. While other factors must also be considered when determining maximum allowable exit separations, these results suggest it is not possible to mandate a maximum exit separation without taking into consideration exit type, exit availability and aircraft configuration. This has implications when determining maximum allowable exit separations for wide and narrow body aircraft. It is also relevant when considering the maximum allowable separation between different exit types on a given aircraft configuration.



Fire Modelling Standards/ Benchmark
Report on Phase 1 Simulations

A Grandison, E Galea, M Patel
Fire Safety Engineering Group
University of Greenwich
London SE10 9LS, UK

 

 




Visibility Catchment Area of Exits and Signs

L Filippidis, E Galea, P Lawrence, S Gwynne
Fire Safety Engineering Group
University of Greenwich
London SE10 9LS, UK

  

The purpose of this paper is to introduce the concept of Visibility Catchment Area (VCA) of Exits and Signs to the buildingEXODUS evacuation model. The VCA of Exits and Signs is used to simulate the ability of occupants to redirect towards an exit or a sign once they become aware of it through the presence of signage.




Applying the Local Equivalence Ratio Concept to Fire Field Models

 Z Wang, F Jia, E Galea
Fire Safety Engineering Group
University of Greenwich
London SE10 9LS, UK

 

In this study, the concept of local equivalence ratio is used to predict toxic gas concentration resulting from enclosure fires. The source term of enthalpy is modeled using the heat release rate concept. The concentrations of carbon monoxide, carbon dioxide, hydrocarbon, soot and oxygen are calculated based on the local equivalence ratio. Two experiments are simulated using this relatively simple approach. It is shown that the predictions based on the equivalence ratio concept are in good agreement with the test results.



Predicting the Evaluation Performance of Passenger Ships using Computer Simulation

 E Galea, S Gwynne, D Blackshields, P Lawrence, L Filippidis
Fire Safety Engineering Group
University of Greenwich
London SE10 9LS, UK

 

When designing a new passenger ship or modifying an existing design, how do we ensure that the proposed design is safe from an evacuation point of view? In the wake of major maritime disasters such as the Herald of Free Enterprise and the Estonia, and in light of the growth in the numbers of high density, high-speed ferries and large capacity cruise ships, issues concerned with the evacuation of passengers and crew at sea are receiving renewed interest. In the maritime industry, ship evacuation models offer the promise to quickly and efficiently bring evacuation considerations into the design phase, while the ship is “on the drawing board”. This paper briefly describes the development of the maritimeEXODUS evacuation model with applications to passenger ships and further discusses issues concerning data requirements.




The airEXODUS Evacuation Model and its Application to Aircraft Safety

 E Galea, S Blake, P Lawrence
Fire Safety Engineering Group
University of Greenwich
London SE10 9LS, UK

 

Computer based mathematical models describing the aircraft evacuation process have a vital role to play in the design and development of safer aircraft, the implementation of safer and more rigorous certification criteria, in cabin crew training and post-mortem accident investigation. As the risk of personal injury and the costs involved in performing full-scale certification trials are high, the development and use of these evacuation modelling tools are essential. The airEXODUS evacuation model has been under development since 1989 with support from the UK CAA and the aviation industry. In addition to describing the capabilities of the airEXODUS evacuation model, this paper describes the findings of a recent CAA project aimed at investigating model accuracy in predicting past certification trials. Furthermore, airEXODUS is used to examine issues related to the “60 foot” rule concerning maximum exit separation. Finally, issues relating to the use of evacuation models for certification are discussed.



The AASK Database V3.0: A Database of Human Experience in Evacuation Derived from Air Accident Reports

 E Galea, K Finney, A Dixon, D Cooney, A Siddiqui
Fire Safety Engineering Group
University of Greenwich
London SE10 9LS, UK

 

This paper describes recent developments concerning the Aircraft Accident Statistics and Knowledge (AASK) database i.e. V3.0. The AASK database is a repository of survivor accounts from aviation accidents developed by the Fire Safety Engineering Group of the University of Greenwich with support from the UK CAA. Its main purpose is to store observational and anecdotal data from the actual interviews of the occupants involved in aircraft accidents. Access to the latest version of the database (AASK V3.0) is available over the internet. AASK consists of information derived from both passenger and cabin crew interviews, information concerning fatalities and basic accident details. Also provided with AASK is the Seat Plan Viewer that graphically displays the starting locations of all the passengers –both survivors and fatalities– as well as the exits used by the survivors. Data entered into the AASK database is extracted from the transcripts supplied by the National Transportation Safety Board in the US and the Air Accident Investigation Branch in the UK. The quality and quantity of the data was very variable ranging from short summary reports of the accidents to boxes of individual accounts from passengers, crew and investigators. Data imported into AASK V3.0 comprises information from:

-         55 accidents,

-         1295 individual passenger records from survivors,

-         110 records from cabin crew interview transcripts, and

-         329 records of fatalities (passenger and crew).



A COLLECTION OF PAPERS PRESENTED BY THE 
FIRE SAFETY ENGINEERING GROUP AT THE 
INTERFLAM’2001 CONFERENCE 
EDINBURGH CONFERENCE CENTRE, SCOTLAND 17-19 SEPTEMBER 2001

Collated by E R Galea

 

INTERFLAM’2001 was held at the Edinburgh Conference Centre Scotland from 17-19 September 2001.  The Fire Safety Engineering Group (FSEG) of the University of Greenwich made five presentations at the conference, two papers (concerning automatic dynamic control of CFD based fire simulations and the marine version of the EXODUS evacuation software) and three poster presentations (concerning the representation of signage in evacuation simulation, prediction of toxic gas generation in CFD based fire models, and the importing of CAD drawings into CFD based fire field models). This document is a collection of that work and consists of a copy of each paper and poster.  The work presented represents only a portion of the fire research activities of FSEG.  For more information concerning these activities please contact Prof Ed Galea at the University of Greenwich or visit our web site at http://fseg.gre.ac.uk

 The full conference proceedings may be obtained from the Interscience Communications LTD UK.



A COLLECTION OF PAPERS PRESENTED BY THE
FIRE SAFETY ENGINEERING GROUP
AT THE THIRD TRIENNIAL FIRE AND CABIN SAFETY RESEARCH CONFERENCE
ATLANTIC CITY, USA, 22-25 OCTOBER 2001

Collated by by E R Galea

 

 

The third triennial Fire and Cabin Safety Research Conference was held in the Taj Mahal Casino hotel in Atlantic City from 22-25 October 2001.  The Fire Safety Engineering Group (FSEG) of the University of Greenwich made two presentations at the conference, one on evacuation modelling and the other on the accident data base AASK.  This document contains the text of these two papers.  In addition, a discussion group on certification issues concerning mathematical modelling was held on the 26 October.  FSEG presented material on certification issues and evacuation modelling described in their paper on airEXODUS model contained in this document. 

The work presented represents only a portion of the fire research activities of FSEG.  For more information concerning these activities please contact Prof Ed Galea at the University of Greenwich or visit our web site at http://fseg.gre.ac.uk

The full conference proceedings may be obtained from the FAA.

 



A Procedure for Benchmarking Fire Field Models

A J Grandison, E Galea, M Patel
Fire Safety Engineering Group
University of Greenwich
London SE10 9LS, UK

 

How does an approval authority determine whether a particular fire field model is appropriate to use in fire engineering applications? Currently, there is no objective procedure that assists the approval authority in making such a judgement. The purpose of this project was to define and demonstrate a process for evaluating fire field modelling software. The proposed procedure involved two phases. Phase 1 allowed comparison between different computer codes without the bias of the user or specialist features that may exist in one code and not another. Phase 2 allowed the software developer to perform the test using the best modelling features available in the code to best represent the scenario being modelled. In this way it was hoped to demonstrate that in addition to achieving a common minimum standard of performance, the software products were also capable of achieving improved agreement with the experimental or theoretical results. A significant conclusion drawn from this work suggests that an engineer using the basic capabilities of any of the products tested would be likely to draw the same conclusions from the results irrespective of which product was used. From a regulators view, this is an important result as it suggests that the quality of the predictions produced are likely to be independent of the tool used – at least in situations where the basic capabilities of the software are used.



The Collection and Analysis of Pre-Movement Times Derived from Evacuation Trials Involving University and Hospital premises and their Application to Evacuation Modelling

S Gwynne, E Galea, J Parke, J Hickson
Fire Safety Engineering Group
University of Greenwich
London SE10 9LS, UK

 

This paper presents data relating to occupant pre-movement times from university and hospital outpatient facilities. Although the two structures are entirely different they do employ relatively similar procedures: members of staff sweep areas to encourage individuals to evacuate. However, the manner in which the dependent population reacts to these procedures is quite different. In the hospital case the patients only evacuated once a member of the nursing staff had instructed them to do so, while in the university evacuation, the students were less dependent upon the actions of the staff with over 50% of them evacuating with no prior prompting. In addition, the student response time was found to be dependent on their level of engagement in various activities.



Analysing the Evacuation Procedures Employed on a Thames Pleasure Boat using the maritimeEXODUS Evacuation Model

S Gwynne, E Galea, C Lyster, I Glen
Fire Safety Engineering Group
University of Greenwich
London SE10 9LS, UK

 

On the 19 June 2001, a Thames pleasure boat underwent several evacuation trials. This work was conducted in order to collect data for the validation of marine-based computer models. The trials involved 111 volunteers who were distributed throughout the vessel. The boat has two decks and two point of exit from the lower deck placed on either side of the craft, forward and aft. The boat had a twin set of staircases towards the rear of the craft, just forward of the rear exits. maritimeEXODUS was used to simulate the full-scale evacuation trials conducted. The simulation times generated were compared against the original results and categorised according to the exit point availability. The predictions closely approximate the original results, differing by an average of 6.6 % across the comparisons, with numerous qualitative similarities between the predictions and experimental results. The maritimeEXODUS evacuation model was then used to examine the evacuation procedure currently employed on the vessel. This was found to have potential to produce long evacuation times. maritimeEXODUS was used to suggest modifications to the mustering procedures. These theoretical results suggest that it is possible to significantly reduce evacuation times.



The Use of Evacuation Modelling Techniques in the Design of Very Large Transport Aircraft

E Galea, S Blake, S Gwynne, P Lawrence
Fire Safety Engineering Group
University of Greenwich
London SE10 9LS, UK

 

Very Large Transport Aircraft (VLTA) pose considerable challenges to designers, operators and certification authorities. Questions concerning seating arrangement, nature and design of recreational space, the number, design and location of internal staircases, the number of cabin crew required and the nature of the cabin crew emergency procedures are just some of the issues that need to be addressed. Other more radical concepts such as Blended Wing Body (BWB) design, involving one or two decks with possibly four or more aisles, offer even greater challenges. Can the largest exits currently available cope with passenger flow arising from four or five aisles? Do we need to consider new concepts in exit design? Should the main aisles be made wider to accommodate more passengers? In this paper we demonstrate how computer based evacuation models can be used to investigate these issues through examination of staircase evacuation procedures for VLTA and aisle/exit configuration for BWB cabin layouts.



MaritimeEXODUS Evacuation Analysis of the IMO Day and Night Test Scenarios – A report for the Correspondence Group on Recommendations on Evacuation Analysis for New and Existing Passenger Ships

E Galea, S Gwynne, D Blackshields
Fire Safety Engineering Group
University of Greenwich
London SE10 9LS, UK

 

To examine and compare the capabilities of existing evacuation models two benchmark scenarios were developed by the Correspondence Group on Recommendations on Evacuation Analysis for New and Existing Passenger Ships of the Fire Protection Subcommittee of the International Maritime Organisation (IMO). These correspond to the so-called Day-Case and Night-Case scenarios. This report describes the predictions produced by the maritimeEXODUS V1.0 evacuation model for these two scenarios. The simulations were prepared and analysed by the Fire Safety Engineering Group of the University of Greenwich – developers of the maritimeEXODUS software. The purpose of modelling each scenario was limited to demonstrating the ability of maritimeEXODUS to generate predictions for the time taken to evacuate each deck and to assemble the population on a predefined muster deck. While maritimeEXODUS is capable of modelling many other factors such as the collection of life jackets, the abandonment phase, the impact of fire, etc, these were not considered as part of the IMO problem specification and hence have not been included. Furthermore, no specific evacuation procedures where specified by IMO and so passengers are assumed to take the shortest routes to staircases.



A Semi-Automated Approach to Importing CAD Data into CFD-Based Fire Models

I Frost, M Patel, E Galea
Fire Safety Engineering Group
University of Greenwich
London SE10 9LS, UK

 

The evaluation of the fire safety aspects of buildings is one of the most important parts of the design phase for architects. Over the last decade or two, major advances have been made in the development of tools for assisting architects in the evaluation of building designs. Typically these tools are not interoperable with the Computer Aided Design (CAD) system in which the building is being designed and require re-specification of the building geometry. This paper describes a system which attempts to semi-automate the incorporation of 2D CAD data within the design cycle of modelling tools used, in particular for Computational Fluid Dynamics (CFD) base fire modelling tools.



Using SMARTFIRE to Predict Pre-Flashover Room Fire Temperatures: An analysis of the SMARTFIRE Simulations Undertaken by University of Canterbury

Fuchen Jia, E Galea
Fire Safety Engineering Group
University of Greenwich
London SE10 9LS, UK

 

The University of Canterbury New Zealand undertook a series of SMARTFIRE simulations to compare model predictions against several room fire experiments that were conducted by the University. This document examines this work and extends the analysis with several further simulations. These additional simulations serve to demonstrate the improvement that can be achieved using more appropriate approaches to the modelling of room fire scenarios.



Passenger Behaviour in Aircraft Emergency Situations

E Galea
Fire Safety Engineering Group
University of Greenwich
London SE10 9LS, UK

 

This document represents a review of the current state-of-the-art in our understanding of passenger behaviour during aircraft emergency situations. In formulating this understanding it is essential to separate myth from fact. This is achieved through the careful study of previous aviation accidents, laboratory experimentation and through the analysis of certification evacuation trials. Information from all three sources is reviewed in this document. The report goes on to identify future research issues and challenges facing the research community, aircraft manufacturers and certification authorities, and suggests possible solutions to several issues associated with aircraft evacuation and certification.



An Analysis of Human Behaviour during Aircraft Evacuation Situations using the AASK V3.0 Database

E R Galea, K M Finney, A J P Dixon, D P Cooney and A Siddiqui
Fire Safety Engineering Group
University of Greenwich
London SE10 9LS, UK

  

The Aircraft Accident Statistics and Knowledge (AASK) database is a repository of survivor accounts from aviation accidents. Its main purpose is to store observational and anecdotal data from the actual interviews of the occupants involved in aircraft accidents. The database has wide application to aviation safety analysis, being a source of factual data regarding the evacuation process. It is also key to the development of aircraft evacuation models such as airEXODUS, where insight into how people actually behave during evacuation from survivable aircraft crashes is required. This paper describes recent developments with the database leading to the development of AASK V3.0. These include significantly increasing the number of passenger accounts in the database, the introduction of cabin crew accounts, the introduction of fatality information, improved functionality through the seat plan viewer utility and improved ease of access to the database via the internet. In addition, the paper demonstrates the use of the database by investigating a number of issues associated with aircraft evacuation.



THE DEVELOPMENT OF AN ADVANCED SHIP EVACUATION SIMULATION SOFTWARE PRODUCT AND ASSOCIATED LARGE SCALE TESTING FACILITY FOR THE COLLECTION OF HUMAN SHIPBOARD BEHAVIOUR DATA

E R Galea Fire Safety Engineering Group, University of Greenwich
L Filippidis, Fire Safety Engineering Group, University of Greenwich
S Gwynne, Fire Safety Engineering Group, University of Greenwich
P J Lawrence, Fire Safety Engineering Group, University of Greenwich
G Sharp, Fire Safety Engineering Group, University of Greenwich
D Blackshields, Fire Safety Engineering Group, University of Greenwich
I Glen, Fleet Technology Ltd, BMT, Ottawa, Canada

 

When designing a new passenger ship or modifying an existing design, how do we ensure that the proposed design and crew emergency procedures are safe from an evacuation point of view? In the wake of major maritime disasters such as the Herald of Free Enterprise and the Estonia and in light of the growth in the number of high density, high-speed ferries and large capacity cruise ships, issues concerned with the evacuation of passengers and crew at sea are receiving renewed interest. In the maritime industry, ship evacuation models offer the promise to quickly and efficiently bring evacuation considerations into the design phase, while the ship is “on the drawing board”. maritimeEXODUS – winner of the BCS, CITIS and RINA awards – is such a model. Features such as the ability to realistically simulate human response to fire, the capability to model human performance in heeled orientations, a virtual reality environment that produces realistic visualisations of the modelled scenarios and with an integrated abandonment model, make maritimeEXODUS a truly unique tool for assessing the evacuation capabilities of all types of vessels under a variety of conditions. This paper describes the maritimeEXODUS model, the SHEBA facility from which data concerning passenger/crew performance in conditions of heel is derived and an example application demonstrating the models use in performing an evacuation analysis for a large passenger ship partially based on the requirements of MSC circular 1033.



PREDICTING TOXIC GAS CONCENTRATIONS RESULTING FROM ENCLOSURE FIRES USING THE LOCAL EQUIVALENCE RATIO CONCEPT LINKED TO FIRE FIELD MODELS

 Z Wang, F Jia, E R Galea
Fire Safety Engineering Group
University of Greenwich
30 Park Row
London SE10 9LS, UK

 

A practical CFD method is presented to predict the toxic gases in enclosure fires in this study. The concept of local equivalence ratio is applied in this method. The heat released from combustion is calculated with the volumetric heat source model. The concentrations of carbon monoxide, carbon dioxide, hydrocarbon, soot and oxygen are calculated based on the concept of local equivalence ratio. Two experiments are simulated using this relatively simple approach. It is shown that the predictions based on the local equivalence ratio concept are in good agreement with the test results.



FIRE SAFETY ENGINEERING AND SHIP DESIGN USING ADVANCED FIRE AND EVACUATION SIMULATION

E R Galea, S Gwynne, P J Lawrence, D Blackshields, J Ewer, Z Wang, N Hurst and N Mawhinney
Fire Safety Engineering Group
University of Greenwich
Old Royal Naval College
30 Park Row
London SE10 9LS, UK

 

When designing a new passenger ship or modifying an existing design, how do we ensure that the proposed design and crew emergency procedures are safe from an evacuation resulting from fire or other incident? In the wake of major maritime disasters such as the Scandinavian Star, Herald of Free Enterprise, Estonia and in light of the growth in the number of high density, high-speed ferries and large capacity cruise ships, issues concerning the evacuation of passengers and crew at sea are receiving renewed interest. Fire and evacuation models with features such as the ability to realistically simulate the spread of heat and smoke and the human response to fire as well as the capability to model human performance in heeled orientations linked to a virtual reality environment that produces realistic visualisations of the modelled scenarios are now available and can be used to aid the engineer in assessing ship design and procedures. This paper describes the maritimeEXODUS ship evacuation and the SMARTFIRE fire simulation model and provides an example application demonstrating the use of the models in performing fire and evacuation analysis for a large passenger ship partially based on the requirements of MSC circular 1033.



The Introduction of Social Adaptation within Evacuation Modelling

S Gwynne, E R Galea, P J Lawrence
Fire Safety Engineering Group
University of Greenwich
London SE10 9LS, UK

 

In recent history, a number of tragic events have borne a consistent message; the social structures that existed prior to and during the evacuation significantly affected the decisions made and the actions adopted by the evacuating population in response to the emergency. This type of influence over behaviour has long been neglected in the modelling community. This paper is an attempt to introduce some of these considerations into evacuation models and to demonstrate their impact. To represent this type of behaviour within evacuation models a mechanism to represent the membership and position within social hierarchies is established. In addition, individuals within the social groupings are given the capacity to communicate relevant pieces of data such as the need to evacuate – impacting the response time – and the location of viable exits – impacting route selection. Furthermore, the perception and response to this information is also affected by the social circumstances in which individuals find themselves.



VERRES VLTA Emergency Requirements Research Evacuation Study

E R Galea, S J Blake, S Gwynne
Fire Safety Engineering Group
University of Greenwich
London SE10 9LS, UK

 

In this document we suggest a methodology for the application of computer simulation to the certification of aircraft.  While the approach is intended to address the requirements of Very Large Transport Aircraft, it is applicable to all aircraft types.  The methodology suggested here involves the use of computer simulation, historic certification data, component testing and full-scale certification trials.  The proposed methodology sets out a protocol for how computer simulation should be undertaken in a certification environment and draws on experience from both the marine and building industries. 

Along with the suggested protocol, a phased introduction of computer models to certification is suggested.  Given the sceptical nature of the aviation community regarding any certification methodology change in general, this would involve as a first step the use of computer simulation in conjunction with full-scale testing.  The computer model would be used to reproduce a probability distribution of likely aircraft performance under current certification conditions and in addition, several other more challenging scenarios could be developed.   The combination of full-scale trial, computer simulation (and if necessary component testing) would provide better insight into the actual performance capabilities of the aircraft by generating a performance probability distribution or performance envelope rather than a single datum. Once further confidence in the technique is established, the second step would only involve computer simulation and component testing. This would only be contemplated after sufficient experience and confidence in the use of computer models have been developed.

The third step in the adoption of computer simulation for certification would involve the introduction of more realistic accident scenarios into the certification process. This would require the continued development of aircraft evacuation modelling technology to include additional behavioural features common in real accident scenarios.

Finally, computer based aircraft evacuation models – together with reliable data - have the potential to be used for aircraft certification and provide manufacturers, operators and regulators a means of assessing novel designs, procedures and accident scenarios associated with VLT and BWB (Blended Wing Body) aircraft.



Report on Analysis Conducted by FSEG of Video Footage Derived from the VERRES Evacuation Tests Conducted at  Cranfield on the 25 January and 1 February 2003

E R Galea, S J Blake, A Dixon, S Gwynne
Fire Safety Engineering Group
University of Greenwich
London SE10 9LS, UK

 

This report concerns the analysis undertaken by the University of Greenwich (UoG) on the evacuation data collected as part of the EU funded VERRES project (GMA2/2000/32039).  This data primarily concerns the passenger use of the stairs and passenger exit hesitation time analysis for the upper deck slide.

Unfortunately, the trials did not proceed in the controlled manner that was originally planned and so the analysis did not yield the detailed information that was originally hoped.  The main difficulties associated with these trials were:  

1)      CC did not behave as originally intended.   This meant that it was not possible to (a) measure the propensity of passengers to freely elect to use the staircase and (b) it was not possible to estimate impact of crew influence on passenger stair efficiency and flow rates.  It was apparent that in all the trials, crew played some role in managing the passenger flow on the stairs.

2)      The camera angle for cameras intended to show the passenger stair behaviour on the first day trials were such that three separate cameras would need to be used to investigate passenger performance and behaviour on the stairs. Furthermore, even using these three cameras, a central portion of the stair was missing from view.  While this difficulty was corrected for the second day’s trials, this meant that much of the video footage collected on the first day was either extremely difficult to analyse or not appropriate for analysis.

3)      While the upper deck slide is considerably different to that expected to be used in actual VLTA such as the A380, the passenger exit hesitation times are of interest in aiding our understanding of passenger behaviour.  As these were the first trials to make use of the upper deck slides, the Cranfield crew that staffed the exit exhibited great caution and as such the majority of crew behaviour at the upper deck exits can be described as extremely non-assertive. This crew behaviour significantly biases the behaviour and hence performance of the passengers.  It is thus not clear if the resultant passenger behaviour is a result of the sill height and slide length or the lack of assertiveness of the crew.

However, it is clear from these trials that crew can exert an influence on the performance of passenger stair usage.  Passenger behaviour in utilising the staircase is both rich and complex and warrants further investigation. These trials support the view that for crew to consistently make appropriate or optimal redirection command decisions that include the possibility of using the stairs as part of the evacuation route, they must have sufficient situational awareness.  Equally, passengers can only make appropriate or optimal redirection decisions if they too have sufficient situational awareness.  This situational awareness may need to extend between decks.

Passengers were also noted to make heavy use of the central handrail while both descending and ascending the stairs.  The presence of the central HR effectively created two staircases.  By effectively separating the crowding on the stairs, reducing passenger-passenger conflicts and providing an additional means of passenger stability, it is postulated that the stair flow rates may be positively influence through the presence of the central HR.   Flow rates in the UPWARDS direction was found to be greater than flow rates in the DOWNWARDS direction.  This was thought to be due to the packing densities on the stairs which is a function of the motivation of the passengers, the travel speeds of the passengers and the feed and discharge characteristics of the staircase and surrounding geometry.  It was also noted that the average unit flow rate in the DOWNWARDS direction was equivalent to that specified in the UK Building Regulations.  Clearly, most of the parameters can be influenced by both crew procedures and cabin layout. 

Concerning the passenger exit hesitation times for the higher sill height, the trials produced inconclusive results.  While the exit flow rates are lower and the passenger exit delay times are longer than would be expected for a normal Type-A exit, it is clear that the extreme unassertiveness of the cabin crew positioned at the exits and the lack of motivation of the passengers exerted a strong influence on the data produced.  The reaction of the passengers in these trials was to be expected as the trials were not performed under competitive conditions and the reaction of the cabin crew could also be understood as safety concerns were paramount given that these were the first trials of their type to be conducted at Cranfield. 

Finally, due to the small number of data points provided by these trials, there is insufficient data upon which to claim statistical significance for any of the observations.

Clearly, much more work is required in order to generate essential data to improve our understanding of passenger performance, passenger-crew interaction and passenger-structure interaction within VLTA configurations. 



The Forensic Investigation of Fire Incidents using Computational Fire Engineering Techniques and Experimental Data

H Jiang, S Gwynne, E Galea, P Lawrence, F Jia, H Ingason
Fire Safety Engineering Group
University of Greenwich
London SE10 9LS, UK


This paper examines the application of evacuation modelling tools to forensically analyse a fire scenario similar to the tragic Gothenburg fire incident of 1998. It is not claimed that the analysis accurately reproduces the Gothenburg incident, as a key component required for such a forensic analysis, i.e. the evolution of the fire, is not adequately represented within the evacuation model. However, the model predictions bare a striking resemblance to the events that took place during the actual incident. The model predictions correctly show that the evacuees experienced severe congestion during their attempted evacuation. While over predicting the number of fatalities, the model successfully predicted the fatality order of magnitude. Furthermore, the predicted location of the fatalities matched that found in the actual incident. In addition, the number of injuries sustained due to the interaction of the evacuating population with the deteriorating environmental conditions that was predicted in this scenario matched those produced during the actual incident. The analysis provides insight into the tragic event and an understanding of why so many people died at the Gothenburg incident. Clearly, evacuation and fire simulation models have an important role to play in fire investigation.



Understanding and Modelling the Impact of the Angle of Approach upon the Comprehension of Signage Text

H Xie, L Filippidis, S Gwynne, D Blackshields, P Lawrence, E Galea.
Fire Safety Engineering Group
University of Greenwich
London SE10 9LS, UK


Signage systems are widely used in buildings to provide information for wayfinding, instructions in emergencies, risk location, amongst other things. This paper addresses the visibility of safety signs according to the angle at which they are observed. A theoretical model is developed to explain the relationship of these factors. Experimental trials are performed in order to assess the validity of this model. The experimental findings produced demonstrate a consistency between the theoretical model and the empirical findings. Given this finding, the functionality of the buildingEXODUS model is then extended in accordance with the assumptions on which the theoretical model is based and is then demonstrated using several examples.



The Use of Trial Evacuation Data in the Verification Process of an Evacuation Model and the Subsequent Analysis of Procedural Manipulation.

J Parke, S Gwynne, E Galea, P Lawrence
Fire Safety Engineering Group
University of Greenwich
London SE10 9LS, UK



The collection of data describing the behaviour of evacuees is of fundamental importance to the future development of evacuation models. Data does exist which is amenable for use by evacuation modellers. However, it often requires manipulation to configure it into a useable state, or is presented divorced from the context of its collection. In this paper, data collected from an unannounced trial evacuation is briefly presented. This data is then used as part of a validation exercise for the buildingEXODUS evacuation model. In particular, the data is used to demonstrate the sensitivity of the model to the data provided and to verify the capabilities of the model in accurately representing these scenarios. Given the satisfactory results produced, the model is then used to investigate the consequences of the failure of the procedure applied using the model.



Representing the Influence of Signage on Evacuation behaviour within buildingEXODUS

L Filippidis, E. Galea, S Gwynne, P Lawrence
Fire Safety Engineering Group
University of Greenwich
London SE10 9LS, UK



This paper describes an attempt to introduce occupant interaction with signage systems into evacuation simulation through the newly developed concept of the Visibility Catchment Area or VCA. In this paper we describe the concept of the VCA and how it has been extended to incorporate the presence of physical obstructions and termination distance. The VCA concept is then linked to a prototype behaviour model intended to represent the occupant’s interaction with the signage system. The functionality and performance of the newly developed model is then demonstrated through the simulation of various evacuation scenarios within a hypothetical supermarket layout.



Collection and Analysis of Pre-Evacuation Time Data Collected from Evacuation Trials Conducted in Library Facilities in Brazil

R Machado Tavares, S Gwynne, E Galea
Fire Safety Engineering Group
University of Greenwich
London SE10 9LS, UK

Two evacuation trials were conducted within Brazilian library facilities by FSEG staff in January 2005. These trials represent one of the first such trials conducted in a Brazilian library facility The purpose of these evacuation trials was to collect pre-evacuation time data from a population with a cultural background different to that found in Western Europe. In total some 34 pre-evacuation times were collected from the experiments and these ranged from 5 to 98 seconds with a mean pre-evacuation time of 46.7 seconds.

 


 A Collection of Papers presented by the FSEG at the International Fire & Cabin Safety Research Conference 29/10 – 1/11 2007

 

PREFACE

The Fifth Triennial International Fire and Cabin Safety Research Conference was held in Atlantic City USA 29 Oct – 1 Nov 2007. The Fire Safety Engineering Group (FSEG) of the University of Greenwich made three presentations at the conference.

This document is a collection of that work and consists of a copy of each of the presented papers. The work presented represents only a small proportion of the fire research activities of FSEG.

For more information concerning these activities please contact Professor Ed Galea at the University of Greenwich or visit our web site at http://fseg.gre.ac.uk

The full conference proceedings may be found on the FAA web site at:
http://www.fire.tc.faa.gov/2007Conference/conference.asp
 

 


 Principles and Practice of Evacuation Modelling (9th Edition) - A Collection of Lecture Notes for a Short Course Prepared by the Fire Safety Engineering Group, University of Greenwich

 

PREFACE


The ability to enable efficient circulation of people in heavily populated enclosures is important to the day to day operation of large commercial buildings such as airport terminals, railway and underground stations, shopping malls and cinemas. More importantly, it is an essential design feature in the event of emergency situations.

As architects continue to implement novel concepts in building design, they are increasingly finding that the fixed criteria of the traditional methods of prescriptive building codes are too restrictive. This is due in part to their almost total reliance on configurational considerations such as travel distance and exit width. Furthermore, as these traditional prescriptive methods are insensitive to human behaviour or likely fire scenarios, it is unclear if they indeed offer the optimal solution in terms of evacuation efficiency.

The emergence of performance based building codes together with computer based evacuation models offer the potential of overcoming these shortfalls and addressing the needs not only of the designers but also the legislators. However, if such models are to make a useful contribution they must address the configurational, environmental, behavioural and procedural aspects of the evacuation process.

Over the past 15 years, a variety of different modelling methodologies have been developed to represent the evacuation process. Furthermore, within these various modelling methodologies, there are a number of ways in which to represent the enclosure, population and the behaviour of the population. The myriad approaches which are available have led to the development of some 22 different evacuation models which are currently available. However, while the modelling tools have proliferated, there has not been a corresponding transfer of knowledge and understanding of the discipline from the model developer to the general user. It is a serious shortfall of which the lack of suitable engineering courses dealing with the subject is symptomatic, if not the cause.

Simply possessing a computer to run the models is not enough to exploit these sophisticated tools. They can too easily become 'black boxes' producing magic answers in exciting colour graphics and client-satisfying 'virtual reality' imagery. As well as a fundamental understanding of the range of human psychological and physiological responses to fire, the fire safety engineer must have at least a rudimentary understanding of the theoretical basis supporting evacuation models to appreciate their limitations and capabilities.

The five day short course, ‘Principles and Practice of Evacuation Modelling’ run by the University of Greenwich attempts to bridge the divide between the model developer and the general user, providing them with the expertise they need to understand evacuation modelling. These concepts and techniques are introduced and demonstrated in a series of seminars. Those attending, also gain experience in using the methods during “hands-on” tutorial and workshop sessions.

On completion of this short course, those participating should:

- be familiar with the range of human psychological and physiological responses to fire;
- be familiar with evacuation model assumptions;
- have an understanding of the capabilities and limitations of evacuation modelling software;
- be able to use evacuation modelling software to assess the egress performance of a structure under fire conditions;
- be able to interpret model predictions.

The result is that the fire safety engineer is empowered to realise the full value of mathematical models to help in the prediction of human behaviour during evacuation, and to determine the consequences of fire under a variety of conditions. This in turn enables them to design and implement safety measures, which can potentially control, or at the very least reduce, the impact of fire.
The contents of this course are based on the work of the FSEG EXODUS Development Group which consists of Prof. E Galea, Dr P Lawrence, Mr L Filippidis, Mr Darren Blackshields, Mr David Conney and Mr Gary Sharp. Prof. Galea is indebted to the members of the group for their invaluable assistance in developing the lecture and tutorial material. In particular, the lecture material draws on a number of publications produced jointly by all the members of the group. Finally, Professor Galea is indebted to the tireless effort of Mrs Françoise Barkshire who managed the organisation of the course.


Professor Ed Galea
Director Fire Safety Engineering Group
Course Co-Ordinator.
 

 


 Principles and Practice of Fire Modelling (11th Edition) - A Collection of Lecture Notes for a Short Course Prepared by the Fire Safety Engineering Group, University of Greenwich

 

PREFACE


Once the preserve of university academics and research laboratories with high-powered and expensive computers, the power of sophisticated mathematical fire models has now arrived on the desk top of the fire safety engineer. It is a revolution made possible by parallel advances in PC technology and fire modelling software. But while the tools have proliferated, there has not been a corresponding transfer of knowledge and understanding of the discipline from expert to general user. It is a serious shortfall of which the lack of suitable engineering courses dealing with the subject is symptomatic, if not the cause.

The computational vehicles to run the models and an understanding of fire dynamics are not enough to exploit these sophisticated tools. Too often, they become ‘black boxes’ producing magic answers in exciting three-dimensional colour graphics and client-satisfying ‘virtual reality’ imagery.

As well as a fundamental understanding of the physics and chemistry of fire, the fire safety engineer must have at least a rudimentary understanding of the theoretical basis supporting fire models to appreciate their limitations and capabilities. The five day short course, ‘Principles and Practice of Fire Modelling’ run by the University of Greenwich attempts to bridge the divide between the expert and the general user, providing them with the expertise they need to understand the results of mathematical fire modelling. The course and associated text book, ‘Mathematical Modelling of Fire Phenomena’ are aimed at students and professionals with a wide and varied background, they offer a friendly guide through the unfamiliar terrain of mathematical modelling.

These concepts and techniques are introduced and demonstrated in seminars. Those attending also gain experience in using the methods during “hands-on” tutorial and workshop sessions.

On completion of this short course, those participating should:
- be familiar with the concept of zone and field modelling;
- be familiar with zone and field model assumptions;
- have an understanding of the capabilities and limitations of modelling software packages for zone and field modelling;
- be able to select and use the most appropriate mathematical software and demonstrate their use in compartment fire applications; and
- be able to interpret model predictions.

The result is that the fire safety engineer is empowered to realise the full value of mathematical models to help in the prediction of fire development and to determine the consequences of fire under a variety of conditions. This in turn enables him or her to design and implement safety measures, which can potentially control or at the very least reduce the impact of fire.

Professor Ed Galea
Director Fire Safety Engineering Group
Course Coordinator.

 


17th Annual Proceedings of the Post Graduate Research Seminar Series – No. 17, academic year 2007-2008

 

Foreword


This volume collates the seminar presentations of postgraduate MPhil/PhD students in the school of Computing and Mathematical Sciences (CMS) of the University of Greenwich. As befits a large multi-disciplinary school, the presentations cover work in a number of topics, including Computational Science and Engineering, Fire Safety Science and Engineering, Computer Science, Internet Technology, Mathematics and Statistics.

The dissemination of research findings is an important activity in the scientific process. For this reason, emphasis is given to the development of appropriate skills for trainee researchers. Each student is expected to contribute at least one 30 minute seminar presentation each year. In this presentation the student has the opportunity to expose his/her progress to colleagues who act as a critical audience. Attendance to the seminars is compulsory and it is part of the education and development of all students.

Since obtaining a PhD is a 3-4 year process, a natural progress is evident (and expected) in the content of presentations. First year students are just making the first steps in their chosen research subject, whilst final year students are already displaying an expertise appropriate to the Doctorate level. For this reason, different levels of completeness in the work are to be expected, and final concrete conclusions are only perhaps available in the final year. Nevertheless all presentations have great merit as learning tools and still contain a substantial amount of information for the interested reader.

Finally, thanks are due to all the research students and their supervisors for their contribution, throughout the year, to this valuable compilation.


Professor Koulis Pericleous
Postgraduate Tutor
July 2006

 


Principles and Practice of Evacuation Modelling (10th Edition) – A Collection of Lecture Notes for a Short Course Prepared by the Fire Safety Engineering Group, University of Greenwich


Preface


The ability to enable efficient circulation of people in heavily populated enclosures is important to the day to day operation of large commercial buildings such as airport terminals, railway and underground stations, shopping malls and cinemas. More importantly, it is an essential design feature in the event of emergency situations.

As architects continue to implement novel concepts in building design, they are increasingly finding that the fixed criteria of the traditional methods of prescriptive building codes are too restrictive. This is due in part to their almost total reliance on configurational considerations such as travel distance and exit width. Furthermore, as these traditional prescriptive methods are insensitive to human behaviour or likely fire scenarios, it is unclear if they indeed offer the optimal solution in terms of evacuation efficiency.

The emergence of performance based building codes together with computer based evacuation models offer the potential of overcoming these shortfalls and addressing the needs not only of the designers but also the legislators. However, if such models are to make a useful contribution they must address the configurational, environmental, behavioural and procedural aspects of the evacuation process.

Over the past 20 years, a variety of different modelling methodologies have been developed to represent the evacuation process. Furthermore, within these various modelling methodologies, there are a number of ways in which to represent the enclosure, population and the behaviour of the population. The myriad approaches which are available have led to the development of many different evacuation models which are currently available. To put this into perspective, in 1992 there were some six evacuation models that appeared in the literature, by 1998 this had increased to some 22 different models and in 2008 there were some 50 evacuation models cited in the literature, with new ones regularly appearing. However, while the modelling tools have proliferated, there has not been a corresponding transfer of knowledge and understanding of the discipline from the model developer to the general user. It is a serious shortfall of which the lack of suitable engineering courses dealing with the subject is symptomatic, if not the cause.

Simply possessing a computer to run the models is not enough to exploit these sophisticated tools. They can too easily become 'black boxes' producing magic answers in exciting colour graphics and client-satisfying 'virtual reality' imagery. As well as a fundamental understanding of the range of human psychological and physiological responses to fire, the fire safety engineer must have at least a rudimentary understanding of the theoretical basis supporting evacuation models to appreciate their limitations and capabilities.

The five day short course, ‘Principles and Practice of Evacuation Modelling’ run by the Fire Safety Engineering Group of the University of Greenwich attempts to bridge the divide between the model developer and the general user, providing them with the expertise they need to understand evacuation modelling. These concepts and techniques are introduced and demonstrated in a series of seminars. Those attending, also gain experience in using the methods during “hands-on” tutorial and workshop sessions.

On completion of this short course, those participating should:

- be familiar with the range of human psychological and physiological responses to fire;
- be familiar with evacuation model assumptions;
- have an understanding of the capabilities and limitations of evacuation modelling software;
- be able to use evacuation modelling software to assess the egress performance of a structure under fire conditions;
- be able to interpret model predictions.

The result is that the fire safety engineer is empowered to realise the full value of mathematical models to help in the prediction of human behaviour during evacuation, and to determine the consequences of fire under a variety of conditions. This in turn enables them to design and implement safety measures, which can potentially control, or at the very least reduce, the impact of fire.
The contents of this course are based on the work of the FSEG EXODUS Development Group which consists of Prof. E Galea, Dr P Lawrence, Mr L Filippidis, Mr Darren Blackshields, Mr David Conney and Mr Gary Sharp. Prof. Galea is indebted to the members of the group for their invaluable assistance in developing the lecture and tutorial material. In particular, the lecture material draws on a number of publications produced jointly by all the members of the group. Finally, Professor Galea is indebted to the tireless effort of Mrs Françoise Barkshire who managed the organisation of the course.


Prof. Ed Galea
Director Fire Safety Engineering Group
Course Co-Ordinator.

 


Principles and Practice of Fire Modelling (12th Edition) – A Collection of Lecture Notes for a Short Course Prepared by the Fire Safety Engineering Group, University of Greenwich


Preface


Once the preserve of university academics and research laboratories with high-powered and expensive computers, the power of sophisticated mathematical fire models has now arrived on the desk top of the fire safety engineer. It is a revolution made possible by parallel advances in PC technology and fire modelling software. But while the tools have proliferated, there has not been a corresponding transfer of knowledge and understanding of the discipline from expert to general user. It is a serious shortfall of which the lack of suitable engineering courses dealing with the subject is symptomatic, if not the cause.

The computational vehicles to run the models and an understanding of fire dynamics are not enough to exploit these sophisticated tools. Too often, they become ‘black boxes’ producing magic answers in exciting three-dimensional colour graphics and client-satisfying ‘virtual reality’ imagery.

As well as a fundamental understanding of the physics and chemistry of fire, the fire safety engineer must have at least a rudimentary understanding of the theoretical basis supporting fire models to appreciate their limitations and capabilities. The five day short course, ‘Principles and Practice of Fire Modelling’ run by the University of Greenwich attempts to bridge the divide between the expert and the general user, providing them with the expertise they need to understand the results of mathematical fire modelling. The course and associated text book, ‘Mathematical Modelling of Fire Phenomena’ are aimed at students and professionals with a wide and varied background, they offer a friendly guide through the unfamiliar terrain of mathematical modelling.

These concepts and techniques are introduced and demonstrated in seminars. Those attending also gain experience in using the methods during “hands-on” tutorial and workshop sessions.

On completion of this short course, those participating should:
- be familiar with the concept of zone and field modelling;
- be familiar with zone and field model assumptions;
- have an understanding of the capabilities and limitations of modelling software packages for zone and field modelling;
- be able to select and use the most appropriate mathematical software and demonstrate their use in compartment fire applications; and
- be able to interpret model predictions.

The result is that the fire safety engineer is empowered to realise the full value of mathematical models to help in the prediction of fire development and to determine the consequences of fire under a variety of conditions. This in turn enables him or her to design and implement safety measures, which can potentially control or at the very least reduce the impact of fire.

Professor Ed Galea
Director Fire Safety Engineering Group
Course Coordinator.

 


A Collection of Papers presented by the FSEG at the 4rth International Symposium on Human Behaviour in Fire, Cambridge, 13-15 July 2009


Preface


The 4th International Symposium on Human Behaviour in Fire 2009 was held at Robinson College, Cambridge, UK, 13-15 July 2009. The Fire Safety Engineering Group (FSEG) of the University of Greenwich delivered six papers at the conference covering a wide variety of topics including:

• Analysis of WTC evacuation data
• Modelling wayfinding
• Experimental data and computer modelling of pedestrian interaction with emergency signage
• Trial data and computer modelling of escalator usage for evacuation
• Modelling elevators for evacuation
• Analysis of survey data concerning passenger knowledge of aircraft evacuation

This document is a collection of the six papers presented at the conference. The work presented represents only a portion of the fire research activities of FSEG.

 


A Generalised Relationship between the Normalised Yields of Carbon Monoxide and Hydrogen Cyanide


Abstract


Experimental Studies have demonstrated that there are close correlations between the normalised yields of carbon monoxide (CO) and hydrogen cyanide (HCN) from the combustion of materials containing nitrogen. In this paper, a generalised relationship using the stoichiometric oxygen to fuel mass ratio (SOFMR) is derived to represent these correlations. Using this generalised relationship, the predicted yields of HCN for nylon in tube furnace experiments and HCN concentrations in full-scale cable fire tests are in good agreement with the corresponding measured data. The derived relationship is used to analyse the contributions of CO from different materials in a complex fire reconstruction. The generalised relationship is then used to predict HCN concentrations in two full-scale nylon fires and the predicted concentrations are compared with both experimental data and prediction from a flamelet model. Finally, a method to incorporate the generalised relationship within CFD fire simulations to determine HCN (or CO) concentrations based on measurements of CO (or HCN) yields is presented.

 


Predicting Toxic Gas Concentrations at Locations Remote from the Fire Source


Abstract


A toxicity model capable of predicting toxic gas concentrations within fire enclosures utilising the concept of the Local Equivalence Ratio (LER) was recently developed. The work described in this paper is a continuing development of that model in an attempt to improve the accuracy in predicting species concentrations at remote locations from the room of fire origin. The technique involves dividing the CFD computational domain into two regions for species calculations, a control region and a transport region. The toxic gas concentrations in the control region are calculated using the formulation developed in the earlier study while in the transport region the toxic gas concentrations are determined as a result of the mixing of hot combustion gases with fresh air. In the work presented here, the concept of a critical equivalence ratio, which is derived from the effective heat release rate (or combustion efficiency) of the concerned fire scenario, is introduced to perform the domain division. A reduced scale compartment-hallway hexane fire and a large-scale corridor cable fire, in which high levels of carbon monoxide (CO) concentration are found at locations distant from the original fire sources, are simulated using the modified toxicity model. Predictions of temperatures and species concentrations at various locations follow the measured trends in the experiments. Compared with the earlier model, the modified model provides considerable improvements in the predictions of toxic species levels at remote locations.

 


18th Annual Proceedings of the Post Graduate Research Seminar Series, No. 18 – Academic Year 2008-2009


Foreword


This volume collates the seminar presentations of postgraduate MPhil/PhD students in the school of Computing and Mathematical Sciences (CMS) of the University of Greenwich. As befits a large multi-disciplinary school, the presentations cover work in a number of topics, including Computational Science and Engineering, Fire Safety Science and Engineering, Computer Science, Internet Technology, Mathematics and Statistics.

The dissemination of research findings is an important activity in the scientific process. For this reason, emphasis is given to the development of appropriate skills for trainee researchers. Each student is expected to contribute at least one 30 minute seminar presentation each year. In this presentation the student has the opportunity to expose his/her progress to colleagues who act as a critical audience. Attendance to the seminars is compulsory and it is part of the education and development of all students.

Since obtaining a PhD is a 3-4 year process, a natural progress is evident (and expected) in the content of presentations. First year students are just making the first steps in their chosen research subject, whilst final year students are already displaying an expertise appropriate to the Doctorate level. For this reason, different levels of completeness in the work are to be expected, and final concrete conclusions are only perhaps available in the final year. Nevertheless all presentations have great merit as learning tools and still contain a substantial amount of information for the interested reader.

Finally, thanks are due to all the research students and their supervisors for their contribution, throughout the year, to this valuable compilation.


Professor Koulis Pericleous
Postgraduate Tutor
August 2009

 


Evacuation Response Phase Behaviour


Abstract


It is widely accepted that a key factor which can determine the success of an evacuation is the time it takes for occupants to respond to the notification cues and begin purposeful evacuation movement. However, the two widely used descriptions of response phase behaviour fail to accurately convey the nature of the human factors involved in this process. Furthermore, there is little consensus on the terminology used to describe to Response Phase. In this paper examples of Response Phase behaviours derived from a combination of actual incidents and full-scale evacuation experiments are used as a basis to propose a generalised behavioural description of the Response Phase and propose a terminology that can be used to clearly and succinctly describe the Response Phase.

 


Exploring the Impact of Culture and Staff Intervention on Evacuation Response Phase Behaviour


Abstract


This paper examines the impact of culture – both social and fire – and staff intervention upon Evacuation Response Phase behaviour. As part of this analysis, three separate egress exercises were observed in detail: one in London (UK) and two in Recife (Brazil). Both qualitative and quantitative observations were performed. This enabled two key questions to be addressed: Does culture exert an impact on evacuation response behaviour, in particular response time? What impact does the prompting by staff have upon evacuation response times? The analysis strongly supports the view that staff intervention has a positive effect on reducing occupant response times, reducing average response times, as measured from the sounding of the alarm, by 25% for the prompted group compared to the unprompted group. While not conclusive, the analysis suggests that cultural differences – at least those that exist between the Brazil and the UK – may not be as important an aspect in determining response times as is commonly believed.

 


Principles and Practice of Evacuation Modelling (11th Edition) - A Collection of Lecture Notes for a Short Course Prepared by the Fire Safety Engineering Group, University of Greenwich


Preface

The ability to enable efficient circulation of people in heavily populated enclosures is important to the day to day operation of large commercial buildings such as airport terminals, railway and underground stations, shopping malls and cinemas. More importantly, it is an essential design feature in the event of emergency situations.

As architects continue to implement novel concepts in building design, they are increasingly finding that the fixed criteria of the traditional methods of prescriptive building codes are too restrictive. This is due in part to their almost total reliance on configurational considerations such as travel distance and exit width. Furthermore, as these traditional prescriptive methods are insensitive to human behaviour or likely fire scenarios, it is unclear if they indeed offer the optimal solution in terms of evacuation efficiency.

The emergence of performance based building codes together with computer based evacuation models offer the potential of overcoming these shortfalls and addressing the needs not only of the designers but also the legislators. However, if such models are to make a useful contribution they must address the configurational, environmental, behavioural and procedural aspects of the evacuation process.

Over the past 20 years, a variety of different modelling methodologies have been developed to represent the evacuation process. Furthermore, within these various modelling methodologies, there are a number of ways in which to represent the enclosure, population and the behaviour of the population. The myriad approaches which are available have led to the development of many different evacuation models which are currently available. To put this into perspective, in 1992 there were some six evacuation models that appeared in the literature, by 1998 this had increased to some 22 different models and in 2008 there were some 50 evacuation models cited in the literature, with new ones regularly appearing. However, while the modelling tools have proliferated, there has not been a corresponding transfer of knowledge and understanding of the discipline from the model developer to the general user. It is a serious shortfall of which the lack of suitable engineering courses dealing with the subject is symptomatic, if not the cause.

Simply possessing a computer to run the models is not enough to exploit these sophisticated tools. They can too easily become 'black boxes' producing magic answers in exciting colour graphics and client-satisfying 'virtual reality' imagery. As well as a fundamental understanding of the range of human psychological and physiological responses to fire, the fire safety engineer must have at least a rudimentary understanding of the theoretical basis supporting evacuation models to appreciate their limitations and capabilities.

The five day short course, ‘Principles and Practice of Evacuation Modelling’ run by the Fire Safety Engineering Group of the University of Greenwich attempts to bridge the divide between the model developer and the general user, providing them with the expertise they need to understand evacuation modelling. These concepts and techniques are introduced and demonstrated in a series of seminars. Those attending, also gain experience in using the methods during “hands-on” tutorial and workshop sessions.

On completion of this short course, those participating should:

- be familiar with the range of human psychological and physiological responses to fire;
- be familiar with evacuation model assumptions;
- have an understanding of the capabilities and limitations of evacuation modelling software;
- be able to use evacuation modelling software to assess the egress performance of a structure under fire conditions;
- be able to interpret model predictions.

The result is that the fire safety engineer is empowered to realise the full value of mathematical models to help in the prediction of human behaviour during evacuation, and to determine the consequences of fire under a variety of conditions. This in turn enables them to design and implement safety measures, which can potentially control, or at the very least reduce, the impact of fire.
The contents of this course are based on the work of the FSEG EXODUS Development Group which consists of Prof. E Galea, Dr P Lawrence, Mr L Filippidis, Mr Darren Blackshields, Mr David Conney and Mr Gary Sharp. Prof. Galea is indebted to the members of the group for their invaluable assistance in developing the lecture and tutorial material. In particular, the lecture material draws on a number of publications produced jointly by all the members of the group. Finally, Professor Galea is indebted to the tireless effort of Mrs Françoise Barkshire who managed the organisation of the course.


Prof. Ed Galea
Director Fire Safety Engineering Group
Course Co-Ordinator.

 


A Collection of Papers Presented by the Fire Safety Engineering Group at the PED 2010 Conference, NIST, Maryland, USA, 8-10 March 2010


Preface

(FSEG) of the University of Greenwich made six presentations at the conference: five papers and one poster.

This document is a collection of that work and consists of a copy of each paper and poster. The work presented represents only a portion of the fire research activities of FSEG.

For more information concerning these activities, please contact Professor Ed Galea at the University of Greenwich or visit our web site at http://fseg.gre.ac.uk

 


A Collection of Papers Presented by the Fire Safety Engineering Group at the INTERFLAM’2010 conference


Preface

INTERFLAM’2010 was held at the University of Nottingham, 5-7 July 2010. The Fire Safety Engineering Group (FSEG) of the University of Greenwich made five presentations at the conference: three papers and two posters.

This document is a collection of that work and consists of a copy of each paper and poster. The work presented represents only a portion of the fire research activities of FSEG.

For more information concerning these activities, please contact Professor Ed Galea at the University of Greenwich or visit our web site at http://fseg.gre.ac.uk

The full conference proceedings may be obtained from the Interscience Communications Ltd., UK (Carole Franks c.franks@dial.pipex.com

 


Principles and Practice of Fire Modelling (13th Edition) - A Collection of Lecture Notes for a Short Course Prepared by the Fire Safety Engineering Group, University of Greenwich


Preface

Once the preserve of university academics and research laboratories with high-powered and expensive computers, the power of sophisticated mathematical fire models has now arrived on the desk top of the fire safety engineer. It is a revolution made possible by parallel advances in PC technology and fire modelling software. But while the tools have proliferated, there has not been a corresponding transfer of knowledge and understanding of the discipline from expert to general user. It is a serious shortfall of which the lack of suitable engineering courses dealing with the subject is symptomatic, if not the cause.

The computational vehicles to run the models and an understanding of fire dynamics are not enough to exploit these sophisticated tools. Too often, they become ‘black boxes’ producing magic answers in exciting three-dimensional colour graphics and client-satisfying ‘virtual reality’ imagery.

As well as a fundamental understanding of the physics and chemistry of fire, the fire safety engineer must have at least a rudimentary understanding of the theoretical basis supporting fire models to appreciate their limitations and capabilities. The five day short course, ‘Principles and Practice of Fire Modelling’ run by the University of Greenwich attempts to bridge the divide between the expert and the general user, providing them with the expertise they need to understand the results of mathematical fire modelling. The course and associated text book, ‘Mathematical Modelling of Fire Phenomena’ are aimed at students and professionals with a wide and varied background, they offer a friendly guide through the unfamiliar terrain of mathematical modelling.

These concepts and techniques are introduced and demonstrated in seminars. Those attending also gain experience in using the methods during “hands-on” tutorial and workshop sessions.

On completion of this short course, those participating should:
- be familiar with the concept of zone and field modelling;
- be familiar with zone and field model assumptions;
- have an understanding of the capabilities and limitations of modelling software packages for zone and field modelling;
- be able to select and use the most appropriate mathematical software and demonstrate their use in compartment fire applications; and
- be able to interpret model predictions.

The result is that the fire safety engineer is empowered to realise the full value of mathematical models to help in the prediction of fire development and to determine the consequences of fire under a variety of conditions. This in turn enables him or her to design and implement safety measures, which can potentially control or at the very least reduce the impact of fire.

Professor Ed Galea
Director Fire Safety Engineering Group
Course Coordinator.

 


Principles and Practice of Evacuation Modelling (Twelfth Edition) A Collection of Lecture Notes for a Short Course Prepared by the Fire Safety Engineering Group, University of Greenwich


Preface

The ability to enable efficient circulation of people in heavily populated enclosures is important to the day to day operation of large commercial buildings such as airport terminals, railway and underground stations, shopping malls and cinemas. More importantly, it is an essential design feature in the event of emergency situations.

As architects continue to implement novel concepts in building design, they are increasingly finding that the fixed criteria of the traditional methods of prescriptive building codes are too restrictive. This is due in part to their almost total reliance on configurational considerations such as travel-distance and exit width. Furthermore, as these traditional prescriptive methods are insensitive to human behaviour or likely fire scenarios, it is unclear if they indeed offer the optimal solution in terms of evacuation efficiency.

The emergence of performance based building codes together with computer based evacuation models offer the potential of overcoming these shortfalls and addressing the needs not only of the designers but also the legislators. However, if such models are to make a useful contribution they must address the configurational, environmental, behavioural and procedural aspects of the evacuation process.

Over the past 20 years, a variety of different modelling methodologies have been developed to represent the evacuation process. Furthermore, within these various modelling methodologies, there are a number of ways in which to represent the enclosure, population and the behaviour of the population. The myriad approaches which are available have led to the development of many different evacuation models which are currently available. To put this into perspective, in 1992 there were some six evacuation models that appeared in the literature, by 1998 this had increased to some 22 different models and in 2008 there were some 50 evacuation models cited in the literature, with new ones regularly appearing. However, while the modelling tools have proliferated, there has not been a corresponding transfer of knowledge and understanding of the discipline from the model developer to the general user. It is a serious shortfall of which the lack of suitable engineering courses dealing with the subject is symptomatic, if not the cause.

Simply possessing a computer to run the models is not enough to exploit these sophisticated tools. They can too easily become 'black boxes' producing magic answers in exciting colour graphics and client-satisfying 'virtual reality' imagery. As well as a fundamental understanding of the range of human psychological and physiological responses to fire, the fire safety engineer must have at least a rudimentary understanding of the theoretical basis supporting evacuation models to appreciate their limitations and capabilities.

The five day short course, ‘Principles and Practice of Evacuation Modelling’ run by the Fire Safety Engineering Group of the University of Greenwich attempts to bridge the divide between the model developer and the general user, providing them with the expertise they need to understand evacuation modelling. These concepts and techniques are introduced and demonstrated in a series of seminars. Those attending, also gain experience in using the methods during “hands-on” tutorial and workshop sessions.

On completion of this short course, those participating should:

- be familiar with the range of human psychological and physiological responses to fire;
- be familiar with evacuation model assumptions;
- have an understanding of the capabilities and limitations of evacuation modelling software;
- be able to use evacuation modelling software to assess the egress performance of a structure under fire conditions;
- be able to interpret model predictions.

The result is that the fire safety engineer is empowered to realise the full value of mathematical models to help in the prediction of human behaviour during evacuation, and to determine the consequences of fire under a variety of conditions. This in turn enables them to design and implement safety measures, which can potentially control, or at the very least reduce, the impact of fire.
The contents of this course are based on the work of the FSEG EXODUS Development Group which consists of Prof. E Galea, Dr P Lawrence, Mr L Filippidis, Mr Darren Blackshields, Mr David Cooney and Mr Gary Sharp. Prof. Galea is indebted to the members of the group for their invaluable assistance in developing the lecture and tutorial material. In particular, the lecture material draws on a number of publications produced jointly by all the members of the group. Finally, Professor Galea is indebted to the tireless effort of Mrs Françoise Barkshire who managed the organisation of the course.

Prof. Ed Galea
Director Fire Safety Engineering Group
Course Co-Ordinator.
 


Principles and Practice of Fire Modelling (Fourteenth Edition) A Collection of Lecture Notes for a Short Course Prepared by the Fire Safety Engineering Group, University of Greenwich


Preface

Once the preserve of university academics and research laboratories with high-powered and expensive computers, the power of sophisticated mathematical fire models has now arrived on the desk top of the fire safety engineer. It is a revolution made possible by parallel advances in PC technology and fire modelling software. But while the tools have proliferated, there has not been a corresponding transfer of knowledge and understanding of the discipline from expert to general user. It is a serious shortfall of which the lack of suitable engineering courses dealing with the subject is symptomatic, if not the cause.

The computational vehicles to run the models and an understanding of fire dynamics are not enough to exploit these sophisticated tools. Too often, they become ‘black boxes’ producing magic answers in exciting three-dimensional colour graphics and client-satisfying ‘virtual reality’ imagery.

As well as a fundamental understanding of the physics and chemistry of fire, the fire safety engineer must have at least a rudimentary understanding of the theoretical basis supporting fire models to appreciate their limitations and capabilities. The five day short course, ‘Principles and Practice of Fire Modelling’ run by the University of Greenwich attempts to bridge the divide between the expert and the general user, providing them with the expertise they need to understand the results of mathematical fire modelling. The course and associated text book, ‘Mathematical Modelling of Fire Phenomena’ are aimed at students and professionals with a wide and varied background; they offer a friendly guide through the unfamiliar terrain of mathematical modelling.

These concepts and techniques are introduced and demonstrated in seminars. Those attending also gain experience in using the methods during “hands-on” tutorial and workshop sessions.

On completion of this short course, those participating should:
- be familiar with the concept of zone and field modelling;
- be familiar with zone and field model assumptions;
- have an understanding of the capabilities and limitations of modelling software packages for zone and field modelling;
- be able to select and use the most appropriate mathematical software and demonstrate their use in compartment fire applications; and
- be able to interpret model predictions.

The result is that the fire safety engineer is empowered to realise the full value of mathematical models to help in the prediction of fire development and to determine the consequences of fire under a variety of conditions. This in turn enables him or her to design and implement safety measures, which can potentially control or at the very least reduce the impact of fire.

Professor Ed Galea
Director Fire Safety Engineering Group
Course Coordinator

 


Development of New Prototype railEXODUS Software For Passenger Rail Cars


Introduction

 

1.1 BACKGROUND

One goal of the Federal Railroad Administration (FRA), United States Department of Transportation (USDOT), is to ensure that passenger rail equipment is designed, built and operated with a high level of safety. FRA regulations in Title 49, Code of Federal Regulations (49 CFR), Parts 238, and 239, address the safety of intercity passenger and commuter train occupants in various emergency scenarios, such as collisions, derailments, and/or fire [1,2].

The FRA Office of Research and Development is investigating how to further improve passenger train passenger safety. Specific issues for safe, timely, and effective emergency egress that are being reviewed and evaluated include: the number, location, and operation of emergency exits; emergency lighting; and egress conditions. In addition, FRA is interested in determining the feasibility of applying performance-based emergency evacuation time requirements, such as those of the Federal Aviation Administration (FAA), that specify evacuation times (e.g., 90 seconds from an aircraft) to passenger rail cars [3].

The John A. Volpe National Transportation Systems Center (Volpe Center) USDOT, has contracted with the Fire Safety Engineering Group (FSEG) of the University of Greenwich to develop a prototype railEXODUS egress software that can be used to evaluate the applicability of time-based agress requirements to U.S. passenger rail cars.

1.2 PURPOSE

This document describes the developments to the existing railEXODUS prototype software (prototype railEXODUS V1.0) that have been implemented in order to adapt the EXODUS software for use in predicting egress times from U.S. passenger rail cars.

1.3 OBJECTIVES

The objectives of this contract are to:

1.4 SCOPE

The scope of this task is to extend the capability of the existing prototype railEXODUS V1.0 software to incorporate a capability to simulate the egress of passengers from U.S. passenger rail cars in the following types of scenarios:

The model design and software development utilises data derived from a series of egress experiments conducted by the Volpe Center in 2005 and 2006 [4], and when considered appropriate other publicly available data. This data are also used to verify and validate the new Prototype Software where appropriate. The Prototype Software is currently in alpha version, indicating that it has only undergone in-house testing by FSEG and has not been subjected to external third party beta testing.

1.5 APPROACH

The model design and software development was implemented in three development phases. Each development phase included a verification/validation phase to ensure that the new software performed as intended and was capable of reproducing the available experimental data. The three phases of the software development are:

1.6 REPORT ORGANISATION

The remainder of this report is organised as follows:

1.7 TERMINOLOGY

General terminology used throughout this document is highlighted below. Specific terminology used primarily within a chapter is introduced within that chapter.

Model: Theoretical framework including data used to describe a phenomenon.

Software: Implementation of the model including data in computer code which enables the model to be run on a computer to produce predictions of the outcome of the phenomenon for a prescribed model scenario.

Scenario: A combination of factors which directly affect the egress performance of the passenger rail car population. This includes factors such as: lighting conditions, rail car angle of inclination (i.e., roll and pitch), exit configuration (i.e., location, type and number of available exits), the presence of fire, etc.

Model Scenario: A scenario specifically designed for examination using the new prototype railEXODUS software.

Agent: Representation of an individual person within the computer software.

Software Verification: Process in which it is demonstrated that the software produces results which are consistent with the model design and where available, qualitative observations of real world data.

Software Validation: Process in which it is demonstrated that the software produces predictions which are in agreement with quantitative experimental measurements.

Competitive Egress: Situations in which the egressing population senses a high degree of urgency which tends to make the egress more competitive. In such situations, quicker moving individuals may attempt to overtake slower moving individuals, exit queues may bunch up, some occupants may adopt a-typical paths such as climb over furniture to circumvent slower moving occupants and individuals are less likely to exhibit deference behaviours.

Non-Competitive Egress: Egress situations in which the exiting population does not sense a degree of urgency. This lower sensed degree of urgency may occur during an announced drill or trial, during normal deboarding or even in a real emergency situation if there is no sense of personal risk or immediate threat. In non-competitive egress situations the population may exhibit a long response time, movement rates may be slow, there may be a high level of deference behaviour and people are more likely to be prepared to wait in queues.

Terrain: Terrain relates to the nature of a specified region of space, and the potential impact that I might have on movement of individuals traversing that region.

 


Investigating the Impact of Culture on Evacuation Response Phase Behaviour – The Project BeSeCu Evacuation Experiments


Executive Summary

The aim of the BeSeCu (Behaviour, Security and Culture) project is to investigate cross-cultural and ethnic differences of human behaviour in crisis situations in order to better tailor security related communication, instructions and procedures with a view to improving evacuation and protection. The project was intended to provide human behaviour information useful to first responders, building designers and those involved in the development of emergency operating procedures for buildings. Project BeSeCu was funded by the EU Seventh Framework Programme of security research, BeSeCu (project no. 218324) with a budget of €2.1 million and ran from 2008 to 2011.

The BeSeCu project consisted of two main research streams, a field study involving interviews with people who have experienced crisis situations and a series of experimental evacuation trials. In the field study a cross-cultural survey of individual experiences will be conducted to identify determinants of inter-individual differences in people who have experienced evacuation situations, fire disaster survivors and survivors of similar crisis situations, but also workers and first responders as well as those affected in the community.

The aim of the experimental component of project BeSeCu was to study how people react in an emergency, and to determine whether social culture impacts emergency behaviour. As part of project BeSeCu, three unannounced library evacuations were conducted in the Czech Republic, Turkey and Poland. In addition, the data from these trials was compared with data generated from a similar evacuation conducted previously in the UK. The main purpose of these trials was to examine if social culture influences the manner in which people respond to the call to evacuate. Thus the experimental component of BeSeCu focused on the Response Phase of the evacuation process. A secondary aim of the experimental component of project BeSeCu was to develop evacuation data sets which may be useful to validate evacuation models.

As part of project BeSeCu a series of three unannounced evacuation trials were undertaken at three different locations:

A similar evacuation protocol was implemented at each site. This involved the activation of a voice alarm to initiate the evacuation. The precise wording of the message used in the voice alarm was agreed with each of the three participating sites. As a result, while the message at each site was different, an attempt was made to make them as similar as possible. Each evacuation was unannounced and so staff and students at the three sites did not know beforehand that a trial evacuation was taking place.

The primary data that was collected is in the form of video footage from strategically located video cameras and from participant responses to a post-trial questionnaire. A significant amount of effort was invested in selecting the locations for the video cameras. This was done weeks prior to the trials taking place and was determined through site visits by the FSEG team. The camera locations were determined so as to achieve a good coverage of the occupied library spaces and to ensure that students involved in a variety of activities would be captured. A thorough understanding of the library layout was also necessary in order to ensure that the questionnaire was relevant to the specific trial site.

The evacuation trials were conceived, planned and executed by the Fire Safety Engineering Group (FSEG) of the University of Greenwich. The results generated from the trials were analysed by FSEG and the associated computer simulations were undertaken by FSEG. Various BeSeCu partners and others participated in the planning and execution of the trials, in particular;

The three evacuations that were conducted as part of this project generated detailed Response Phase behaviours for 373 individuals. Combined with the data analysed from the UK evacuation, the Response Phase data set studied in BeSeCu comprised of 477 individuals, 192 from Poland, 51 from Turkey, 70 from the Czech Republic and 104 from the UK. Two comprehensive evacuation model validation data sets were also developed from the Turkish and Polish evacuation trials. The key developments and findings resulting from this work are set out below.

• Response Phase Descriptive Framework
The comparative studies of evacuation behaviour were based not simply on response times but on a framework, developed as part of project BeSeCu, to describe Response Phase behaviours. The framework not only provides a consistent method for describing Response Phase behaviour, but also provides a systematic means for classifying and quantifying the Response Phase other than simply using the overall response time. By understanding and quantifying the factors which influence and ultimately determine the Response Phase we are better able to compare and contrast different evacuation situations.

Based on the Response Phase Behavioural Framework, key parameters that define the Response Phase for each member of the population are:

From these individual parameters a parameter set representative of the population as a whole can be determined by taking the average for each individual parameter. In this way the Response Phase for a particular evacuation can be defined by specifying the average duration of the Notification stage (NT), the average number of Action Tasks (AT) undertaken, the average number of Information Tasks (IT) undertaken, the average duration of an Action Task (ATT), the average duration of an Information and Task (ITT) and the average Response Time (RT).

For a common group of buildings and their populations defined by; building type, nature of notification system, population demographics and levels of population structural familiarity and training, the Response Phase parameter set (i.e. NT, AT, IT, ITT and ATT), and hence the response time distribution, can be expected to be similar for different examples within the group. However, if the Response Phase parameter set and hence the response time distribution are also dependent on culture, it is possible that the response time distributions and Response Phase parameter sets will be different even for buildings from the same group located in different countries.

In addition, the Response Phase Behavioural Framework provides an empirical means of predicting population average response time based on average number of Information/Action tasks, average task duration and average notification time.


• Differences in Response Phase Behaviours
For the four library evacuations conducted in four different countries, differences were noted in the relative trends between Response Phase parameters (NAT, NIT, ATT, ITT and NT) defining the Response Phase parameter set.

Of the four countries, the UK (alarm only) population was the only one of the four national groups whose trends in Response Phase characteristics matches the trends of the national average population. These trends are that the population undertakes more Action than Information tasks and the average duration of an Information Task is greater than the average duration of an Action Task. The Polish and Czech (alarm only) populations match different aspects of the average trend, with the Polish population matching trends in the number of tasks, while the Czech (alarm only) population matches trends in the average duration of the tasks. The Turkish population behaves in a way which is opposite to the national average trends.

Furthermore, trends in the number and duration of Response Phase tasks also differ between the national groups. Consider the country with the longest response times (Czech Republic) and the country with the shortest response times (Turkey). Virtually all the Response Phase parameters for the Czech (alarm only) group are greater than or significantly greater than the national group averages, indicating that this group will take considerably longer in the Response Phase than the national average, and is likely to have the longest response time. For the Turkish group, both the NT and the number of Action Tasks are smaller than the national average and the average duration of both Action and Information Tasks are less than the national group averages. This suggests that the Turkish population is likely to have a shorter Response Phase than the national average, and is likely to have the shortest Response Phase.

• Differences in Response Time Distributions
Statistically significant differences (at the 5% level) were observed in the response time distributions for the four library evacuations conducted in four different countries.

The UK (alarm only) response time data is:

- quicker on average than the Czech Rep (alarm only) response time data.
- slower on average than the Poland response time data.
- slower on average than the Turkey response time data.

The Poland response time data is:

- quicker on average than the Czech Rep (alarm only) response time data.
- slower on average than the Turkey response time data.

The Turkey response time data is:

- quicker on average than the Czech Rep (alarm only) response time data.

On average, the population with the quickest to the slowest response times are: Turkey, Poland, UK and Czech Republic.

• Is Response Phase Behaviour Dependent on Social Culture?
The response time distributions for each of the four libraries have been shown to be statistically significantly different. In addition, trends in and values of the Response Phase parameter sets for the four evacuations have been shown to be different. Furthermore, every effort was made to ensure that the conditions for each evacuation were as similar as possible. This is essential to ensure that as far as possible the main variable that may influence evacuation performance is social cultural. As these trials were full-scale and unannounced, as opposed to laboratory based trials, it is virtually impossible to ensure that conditions are exactly identical in each trial. However, the age, gender and evacuation experience of each population was very similar.

The building type across all three trials was also identical (a library) so as to ensure that the population were involved in similar activities. To a certain extent this was achieved with the majority of people (over 69%) in each library involved in work related activities. However in one case (Polish library), a relatively small proportion of the population (a quarter) was involved in computer work related activities at the time of the alarm compared to the other populations (which had about a half). This may explain why the Polish population had the shortest average notification time. However, the Polish population did not have the shortest average response time and so the differences in the number of people engaged in computer work related activities is not considered significant. While only a single evacuation trial was conducted at each library, this is not considered to be significant as there is some evidence to suggest that response time distributions derived from one trial can be expected to be representative of the scenario (defined by building type, notification system and population) being considered. However, of more significance is the fact that a different notification system (alarm) was used it the UK trial compared to the other three trials. As the nature of the alarm system is expected to have a significant impact on the response time distribution, it can be argued that the UK data set should be excluded from the cross-cultural comparison.

Given that the parameters that influence Response Phase behaviour and performance (e.g. population: level of familiarity and training, age distribution and gender mix and type of structure) were reasonably controlled, it is possible that the observed significant differences in response time distributions and the differences in Response Phase parameters are the result of cultural influences on Response Phase behaviour. This conclusion is valid for the three BeSeCu libraries (Turkey, Czech Republic and Poland) and may also be valid for the fourth library (UK). Further work is required before a definitive link between social culture and evacuation behaviour can be established.

• Impact of Different National Response Time Data on Evacuation
While the response time distributions for the four national groups have been shown to be statistically significantly different it is not clear what impact these differences would have on an evacuation simulation. In order to assess the impact of these different response time distributions they were each applied in turn to the Turkish library evacuation and the buildingEXODUS evacuation simulation software was used to gauge the impact these different response time distributions would have on the evacuation.

The four evacuation simulations produced using the four national response time distributions resulted in very different evacuation predictions. Even in the best case (comparing the Turkish prediction with the Polish prediction), differences in evacuation times can be between 2% to 28%. In the worst case, (comparing the Turkish prediction with the Czech prediction), differences in evacuation times can be as much as 66% to 93%. Thus if significant differences in national representative response time distributions exist, they can lead to very different evacuation outcomes. It is thus important to ensure that the response time distribution used in computer egress simulations in different countries are representative of that national group.

• Predictive Response Time Model
An empirical response time model, based on the Response Phase parameter set (NAT, NIT, ATT, ITT and NT) was developed and applied to the evacuation trial data. For four different evacuations in four different countries the predictive response time model was able to predict the measured average response time within: 1.6% in the Czech Republic evacuation trial, 11.3% in the Turkey evacuation trial, 3.0% in the Poland evacuation trial and 3.9% within the UK evacuation trial. The average error across all four trials is 5.0%.

Thus the constants used in the empirical response time model appear to be reasonably robust, providing a good level of agreement for four evacuation trials conducted in four different libraries in four different countries. Of more importance is the insight it provides into the behavioral factors driving the response time. Using this approach it should be possible to estimate the impact of introducing technical or procedural measures to address various behavioral determinants of response time such as the duration of the average Information Task, or the number of Information Tasks that are performed by a population.

• Validation Data Sets
Two evacuation data sets, based on the Turkish and Polish library evacuations, suitable for the validation of evacuation models have been developed. The Turkish validation data set involves the evacuation of the entire library and consists of exit flow data for each of the two exits. The Polish validation data set involves a sub-set of the full library evacuation incorporating the portion of the library just in front of the library main exit, between the base of the main entrance stairs and the main exit and consists of exit flow data and the transient change in the population density just ahead of the exit.

Both validation data sets are unique in their own way. Unlike most evacuation model validation data sets, the Turkish data set incorporates regional information relating to the starting locations of the population and regional response times for the population. Most evacuation validation data sets lack these essential details allowing modellers the opportunity to tune their predictions in order to obtain the best fit to the experimental results. Furthermore, most evacuation model validation data sets only test model predictions of exit flows, whereas the Polish data set provides data describing the transient variation of population densities, allowing a more detailed analysis of model predictions.

The Turkish evacuation data set provides a comprehensive validation data set, uniquely including regional starting locations and response time distributions for the population, for a complex multi-floor building. As such, the data set is an important contribution to the development of evacuation models. The simulations of the Turkish evacuation using the buildingEXODUS software demonstrate that this evacuation modelling tool is capable of reproducing the measured results of the evacuation with a high degree of accuracy.

The Polish evacuation data provides a validation data set for evacuation models which includes transient density measurements along with the standard exit curve. While the geometry of the validation data set is small it uniquely provides a means of gauging the ability of evacuation simulation software to predict transient population density variations in the exit flow. As such, the data set is an important contribution to the development of evacuation models. The simulations of the Polish evacuation using the buildingEXODUS software demonstrate that this evacuation modelling tool is capable of reproducing the measured exiting times to within 5.8% and is capable of predicting the transient density variations to a good degree of accuracy. This indicates that the software is capable of resolving the crowd dynamics associated with congestion in the flow domain and the exiting behaviour.

• Observations Relating to the Response Phase
The detailed analysis of the BeSeCu and related evacuation data allowed a number of important observations to be made concerning evacuation behaviour. These include:

o Average Response Phase behaviours

Taken across all four evacuations, on average university library populations:

o Impact of pre-alarm activity on Notification Time

Across all four evacuation trials it was noted that occupants engaged in computer related work activities incur longer delays in disengaging from work related activities on the sounding of the alarm than those engaged in other types of work activities. Hence being engaged in computer activities may lead to longer notification times and hence longer response times. Notification times for those engaged in computer related work are between 14% and 175% longer than those involved in other work related activities.

o Alarm Vs Staff Intervention

In the Czech evacuation part of the population was exposed only to a voice alarm and part only to staff intervention. This provided a good opportunity to compare and contrast the response behaviours of the two populations. Compared to the staff intervention population, the alarm only population:

All of this explains why the alarm only population has an average response time 4.5X greater than the staff intervention population. The results for the Czech population confirm the commonly held belief that relative response times for populations exposed to staff intervention will be shorter than those exposed to an alarm only. However, it must be noted that the response times reported here do not include the time required for the staff member to respond to the alarm and travel to the population location. If these times are taken into consideration, the absolute response time for the population exposed to staff intervention may be greater than that for the population exposed only to the alarm.

o Alarm and Staff Intervention

In the UK evacuation some of the population was exposed to both the alarm and staff intervention. In such cases, staff intervention is intended to shorten the response phase of those individuals that may take excessive time responding. The staff intervention process achieves this by reducing the targeted occupants Notification stage or Activity stage or both stages. Evidence supporting this view was collected from the UK evacuation trial. In this trial the staff intervention population consisted of two distinct sub-groups.

The first sub-group had exceptionally long Notification times, the group effectively ignoring the alarm. However, this sub-group disengaged from their pre-alarm activities shortly after staff intervention. Clearly, this sub-group was intent on completing their pre-alarm activities. However, without staff intervention, these individuals may have incurred even longer Notification times. So staff intervention may have resulted in these individuals completing the Notification stage sooner than would otherwise have occurred. The response time for this sub-group was significantly longer than that for the alarm only group, but may have been even longer without the staff intervention. For this group, staff intervention potentially reduced what are exceptionally long Notification times from being even longer and reduced the duration of the Activity stage. Had the staff intervention occurred earlier, the notification time may have been even shorter.

The second sub-group had completed the Notification stage and commenced the Activity stage well before any staff members appeared. For this group the Notification time was extremely short and was not influenced by the staff intervention. However, this sub-group undertook more tasks during the Activity stage (10.7) than the alarm only population (8.8). It is possible that the staff intervention prevented even more tasks from being undertaken during the Activity Stage, preventing the Activity stage from taking even longer. The response time for this group was marginally longer than that for the alarm only group (92 sec). For this group, staff intervention potentially reduced the duration of the Activity stage.

o Group Behaviour

From the Turkish and Polish evacuation, the response to the questionnaires suggests that when first alerted by the alarm about half the population were in groups of friends, a third were alone and about a fifth were in groups of strangers. If you were in a group of friends prior to the alarm, it was likely that you evacuated in a group and that you exited in a group whereas if you were in a group of strangers, it is likely that you separated from the group and evacuated alone. Thus the bond between groups of friends is seen to be much stronger than the group bond between strangers during the evacuation. Furthermore, if you were alone prior to the alarm, you were very likely to evacuate alone. Clearly group behaviour is an important aspect of evacuation and requires further research.

o How representative is a response time distribution derived from a single trial?

It is conjectured that repeat evacuation trials in a given structure with a different but similar population (i.e. a population that has similar demographics and key characteristics) will produce similar response time distributions. Evidence to support this view was presented from the EF FP7 SAFEGUARD project which involved two evacuation trials on a large passenger ferry involving a range of accommodation including; business and traveller class seating areas (airline style seating), large retail and restaurant/catering areas, bar areas, in-door and out-door general seating areas and general circulation spaces. The trials were conducted on two days with two different but similar populations. The two response time distributions were made up from 533 and 470 individual response times respectively. Mann-Whitney testing performed on the pair of data sets revealed that there is not a significant difference between the pair of response time distributions at the 5% significance level. As the response time distribution is a statistical construct – unlike the evacuation exit curve – it is more likely to be invariant with respect to repeat trials.

o The impact on validation simulations of uncertainties in occupant response time distributions and starting locations.

The sensitivity of evacuation model predictions with respect to uncertainties in occupant response times and starting locations was assessed using the Turkish library validation data set. This data set consisted of an unannounced evacuation from a two floor structure consisting of two staircases, two exits and 100 occupants. Analysis suggested that using a global rather than a local response time distribution can introduce sizeable discrepancies (between 2% and 22%) in the numerical predictions. Greater discrepancies (between 3% and 33%) are introduced when the starting locations of the agents are randomised and the global response time distributions are used. Perhaps of greater concern, by randomising the starting locations of the population within the simulation, the exits and hence exit paths taken by the agents are different to those in the evacuation experiment, and so even the evacuation dynamics within this simulation are potentially different to that of the experiment.

Furthermore, the differences in apparent accuracy of the predictions are generated by the same software tool simply by introducing uncertainties in the initial conditions. Thus it is possible to come to different conclusions on the suitability of the evacuation software in reproducing the trial data based on the quality of the initial scenario specification data. To truly gauge the ability of an evacuation model to accurately predict the outcome of an evacuation, validation data sets should include accurate information relating to the starting locations of the population and individual response time data, or at the least, regional response time and starting location data. Without this type of information uncertainties of between 3% and 33% or greater are possible even if the software is capable of producing perfect agreement with the experimental data.

o Impact of fire culture on evacuation performance

In the BeSeCu evacuation trials, the impact of fire culture on the outcome of Response Phase and evacuation performance was controlled, for the most part, through the intervention of the FSEG research team. However, in the event of a real emergency, the noted deficiencies in fire culture could be expected to adversely contribute to evacuation performance. Noted short comings in fire culture included: