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Dissertations / Theses on the topic 'Flame spread Fire'
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1
Lewis, M. J. "Field modelling of flame spread for enclosure fires." Thesis, Cranfield University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264350.
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Kwon, Jaewook. "Evaluation of FDS V.4: Upward Flame Spread." Digital WPI, 2006. https://digitalcommons.wpi.edu/etd-theses/1022.
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"NIST's Fire Dynamics Simulator (FDS) is a powerful tool for simulating the gas phase fire environment of scenarios involving realistic geometries. If the fire engineer is interested in simulating fire spread processes, FDS provides possible tools involving simulation of the decomposition of the condensed phase: gas burners and simplified pyrolysis models. Continuing to develop understanding of the capability and proper use of FDS related to fire spread will provide the practicing fire engineer with valuable information. In this work three simulations are conducted to evaluate FDS V.4's capabilities for predicting upward flame spread. The FDS predictions are compared with empirical correlations and experimental data for upward flame spread on a 5 m PMMA panel. A simplified flame spread model is also applied to assess the FDS simulation results. Capabilities and limitations of FDS V.4 for upward flame spread predictions are addressed, and recommendations for improvements of FDS and practical use of FDS for fire spread are presented."
3
Kwon, Jae-Wook. "Evaluation of FDS V.4 -- Upward flame spread." Link to electronic thesis, 2006. http://www.wpi.edu/Pubs/ETD/Available/etd-090606-112948/.
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Kim, Dong-Hyun. "A Study for Surface Fire Behavior and Flame Spread Model in Forest Fire." 京都大学 (Kyoto University), 2010. http://hdl.handle.net/2433/120907.
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Musluoglu, Eren. "A Theoretical Analysis Of Fire Development And Flame Spread In Underground Trains." Phd thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/12610860/index.pdf.
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The fire development and flame spread in the railway carriages are investigated by performing a set of simulations using a widely accepted simulation software called ‘
Fire Dynamics Simulator&
#8217
. Two different rolling stock models
representing a train made up of physically separated carriages, and a 4-car train with open wide gangways
have been built to examine the effects of train geometry on fire development and smoke spread within the trains. The simulations incorporate two different ignition sources
a small size arson fire, and a severe baggage fire incident. The simulations have been performed incorporating variations of parameters including tunnel geometry, ventilation and evacuation strategies, and combustible material properties. The predictions of flame spread within the rolling stock and values of the peak heat release rates are reported for the simulated incident cases. In addition, for a set of base cases the onboard conditions are discussed and compared against the tenability criteria given by the international standards. The predictions of heat release rate and the onboard conditions from the Fire Dynamics Simulator case studies have been checked against the empirical methods such as Duggan&
#8217
s method and other simulation softwares such as CFAST program.
6
Cowlard, Adam. "Sensor and model integration for the rapid prediction of concurrent flow flame spread." Thesis, University of Edinburgh, 2009. http://hdl.handle.net/1842/2753.
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Fire Safety Engineering is required at every stage in the life cycle of modern-day buildings. Fire safety design, detection and suppression, and emergency response are all vital components of Structural Fire Safety but are usually perceived as independent issues. Sensor deployment and exploitation is now common place in modern buildings for means such as temperature, air quality and security management. Despite the potential wealth of information these sensors could afford fire fighters, the design of sensor networks within buildings is entirely detached from procedures associated to emergency management. The experiences of Dalmarnock Fire Test Two showed that streams of raw data emerging from sensors lead to a rapid information overload and do little to improve the understanding of the complex phenomenon and likely future events during a real fire. Despite current sensor technology in other fields being far more advanced than that of fire, there is no justification for more complex and expensive sensors in this context. In isolation therefore, sensors are not sufficient to aid emergency response. Fire modelling follows a similar path. Two studies of Dalmarnock Fire Test One demonstrate clearly the current state of the art of fire modelling. A Priori studies by Rein et al. 2009 showed that blind prediction of the evolution of a compartment fire is currently beyond the state of the art of fire modelling practice. A Posteriori studies by Jahn et al. 2007 demonstrated that even with the provision of large quantities of sensor data, video footage, and prior knowledge of the fire; producing a CFD reconstruction was an incredibly difficult, laborious, intuitive and repetitive task. Fire fighting is therefore left as an isolated activity that does not benefit from sensor data or the potential of modelling the event. In isolation sensors and fire modelling are found lacking. Together though they appear to form the perfect compliment. Sensors provide a plethora of information which lacks interpretation. Models provide a method of interpretation but lack the necessary information to make this output robust. Thus a mechanism to achieve accurate, timely predictions by means of theoretical models steered by continuous calibration against sensor measurements is proposed. Issues of accuracy aside, these models demand heavy resources and computational time periods that are far greater than the time associated with the processes being simulated. To be of use to emergency responders, the output would need to be produced faster than the event itself with lead time to enable planning of an intervention strategy. Therefore in isolation, model output is not robust or fast enough to be implemented in an emergency response scenario. The concept of super-real time predictions steered by measurements is studied in the simple yet meaningful scenario of concurrent flow flame spread. Experiments have been conducted with PMMA slabs to feed sensor data into a simple analytical model. Numerous sensing techniques have been adapted to feed a simple algebraic expression from the literature linking flame spread, flame characteristics and pyrolysis evolution in order to model upward flame spread. The measurements are continuously fed to the computations so that projections of the flame spread velocity and flame characteristics can be established at each instant in time, ahead of the real flame. It was observed that as the input parameters in the analytical models were optimised to the scenario, rapid convergence between the evolving experiment and the predictions was attained.
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Adam, Brittany A. "INCORPORATING DYNAMIC FLAME BEHAVIOR INTO THE SCALING LAWS OF WILDLAND FIRE SPREAD." UKnowledge, 2015. http://uknowledge.uky.edu/me_etds/54.
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A challenge for fire researchers is obtaining data from those fires that are most dangerous and costly. While it is feasible to instrument test beds, test plots, and small prescribed burns for research, it is uncommon to successfully instrument an active wildland fire. With a focus on very specific facets of wildland fire, researchers have created many unique models utilizing matchsticks, cardboard, liquid fuel, excelsior, plywood, live fuels, dead fuels, and wood cribs of different packing densities. Such scale models, however, only serve as valid substitutes for the full-scale system when all functional relations of the scale model are made similar to corresponding relations of the original phenomena. The field of study of large wildland fires therefore was in need of a framework that researchers could use to relate the results from many previous experiments to full-scale wildland fires; this framework was developed during the research for this dissertation. This further work developing laws for instability scaling in wildland settings was founded on the established work in dynamic similitude of G.I. Taylor, H. C. Hottel, F. A. Williams, R. I. Emori, K. Saito and Y. Iguchi. Additionally, in this work, a new dynamic flame parameter was incorporated into the scaling laws for fires that had not previously been assessed and proved to provide additional, important insight into flame spread. The new dynamic parameter enabled improved St-Fr correlations and was established for a wide range of fire sizes and fuel types.
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Park, Jeanhyuk. "NUMERICAL STUDY OF CONCURRENT FLAME SPREAD OVER AN ARRAY OF THIN DISCRETE SOLID FUELS." Case Western Reserve University School of Graduate Studies / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=case151492595770856.
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Li, Qian. "NUMERICAL STUDY OF FIRE BEHAVIOR BETWEEN TWO INCLINED PANELS." Case Western Reserve University School of Graduate Studies / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=case1560241654377726.
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Shi, Yan Safety Science Faculty of Science UNSW. "A model for the (QUASI) steady flame spread on vertical and horizontal surface." Publisher:University of New South Wales. Safety Science, 2008. http://handle.unsw.edu.au/1959.4/41435.
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Initial fire spread is composed of the processes of ignition, flame spread, and burning rate. The effects of a material's thermal characteristics and burning behaviors on flame spread are important. However, many zone and field models of compartment fire can not predict spread on objects accurately enough due to the neglect of these behaviors in their fire growth sub-models. As a result, a model dedicated to the early stage of fire growth is needed to provide the accuracy necessary for competent assessment of the response of safety systems, as well as satisfying the requirement for a comprehensive risk assessment. This study is undertaken to investigate the use of formulations outlined by previous researchers by review of the theory of flame spread models. A computer model is proposed that can determine the impact of the material properties with emphasis on practical engineering analyses. Through this computer program, we can obtain the pyrolysis zone, the flame height, the burnout time, the burnout portion, the mass loss rate, total heat release rate, and mean flame velocity of a material at specific time. The effort in this study has been focused on developing a relatively simple model for fire spread on a vertically oriented material which contains the most common aspect of fire growth theory such as the transit burning rate, material properties, burner affection, flame spread rate and burnout. This study used Vc++ as a program development platform which has an easy to use interface and reasonable execution times. The model is a combination of two sub-models. One is to simulate the flame spread on horizontal surface. The other is to simulate it on a vertical surface. In two sub-models, the spread process model is two-dimensioned yet symmetric. By using empirical physical equations and correlations, this model predicted flame spread by solving a set of closed coupled correlations simultaneously. Each sub-model contains several functions: ignition, mass loss rate calculation, burning area and the surface temperature calculation. The results of this proposed computer model are compared with experimental studies involving a limited number of comparisons of experimental data for early stage vertical flame spread. The model calculations and experimental measurements of the mass loss rate, heat release rate, and radiation flux were found to be in good agreement. Recommendations are made for further development of the more complex initial stage fire growth model.
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Wright, Mark T. "Flame spread on composite materials for use in high speed craft." Link to electronic version, 1999. http://www.wpi.edu/Pubs/ETD/Available/etd-110599-160802/.
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Pehrson, Richard. "Prediction of fire growth on furniture using CFD." Link to electronic version, 1999. http://www.wpi.edu/Pubs/ETD/Available/etd-052099-131146/.
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Alston, Jarrod John. "Room/Corner Fire Calibration Data: Marine Composite Screening Specimens." Link to electronic thesis, 2004. http://www.wpi.edu/Pubs/ETD/Available/etd-0527104-180727/.
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Fleury, Rob. "Evaluation of Thermal Radiation Models for Fire Spread Between Objects." Thesis, University of Canterbury. Civil and Natural Resources Engineering, 2010. http://hdl.handle.net/10092/4959.
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Fire spread between objects within a compartment is primarily due to the impingement of thermal radiation from the fire source. In order to estimate if or when a remote object from the fire will ignite, one must be able to quantify the radiative heat flux being received by the target. There are a variety of methods presented in the literature that attempt to calculate the thermal radiation to a target; each one based on assumptions about the fire.
The performance of six of these methods, of varying complexity, is investigated in this research. This includes the common point source model, three different cylindrical models, a basic correlation and a planar model. In order to determine the performance of each method, the predictions made by the models were compared with actual measurements of radiant heat flux. This involved taking heat flux readings at numerous locations surrounding a propane gas burner. Different fire scenarios were represented by varying the burner geometry and heat release rate. Video recordings of the experiments were used to determine the mean flame heights using video image analysis software.
After comparing the measured data with predictions made by the theoretical radiation methods, the point source model was found to be the best performing method on average. This was unexpected given the relative simplicity of the model in comparison to some of its counterparts. Additionally, the point source model proved to be the most robust of the six methods investigated, being least affected by the experimental variables. The Dayan and Tien method, one of the cylindrical models, was the second most accurate over the range of conditions tested in this work.
Based on these findings, recommendations are made as to the most appropriate method for use in a radiation sub-model within an existing zone model software. The accuracy shown by the point source model, coupled with its ease of implementation, means that it should be suitable for such a use.
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Wong, William Chiu-Kit. "CFD Flame Spread Model Validation: Multi-Component Data Set Framework." Digital WPI, 2012. https://digitalcommons.wpi.edu/etd-theses/918.
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"Review of the literature shows that the reported correlation between predictions and experimental data of flame spread vary greatly. The discrepancies displayed by the models are generally attributed to inaccurate input parameters, user effects, and inadequacy of the model. In most experiments, the metric to which the model is deemed accurate is based on the prediction of the heat release rate, but flame spread is a highly complex phenomenon that should not be simplified as such. Moreover, fire growth models are usually made up of distinctive groups of calculation on separate physical phenomena to predict processes that drive fire growth. Inaccuracies of any of these “sub-models” will impact the overall flame spread prediction, hence identifying the sources of error and sensitivity of the subroutines may aid in the development of more accurate models. Combating this issue required that the phenomenon of flame spread be decomposed into four components to be studied separately: turbulent fluid dynamics, flame temperature, flame heat transfer, and condensed phase pyrolysis. Under this framework, aspects of a CFD model may be validated individually and cohesively. However, a lack of comprehensive datasets in the literature hampered this process. Hence, three progressively more complex sets of experiments, from free plume fires to fires against an inert wall to combustible wall fires, were conducted in order to obtain a variety of measurements related to the four inter-related components of flame spread. Multiple permutations of the tests using different source fuels, burner size, and source fire heat release rate allowed a large amount of comparable data to be collected for validation of different fire configurations. FDS simulations using mostly default parameters were executed and compared against the experimental data, but found to be inaccurate. Parametric study of the FDS software shows that there are little definitive trends in the correlation between changes in the predicted quantities and the modeling parameters. This highlights the intricate relationships shared between the subroutines utilized by FDS for calculations related to the four components of flame spread. This reveals a need to examine the underlying calculation methods and source code utilized in FDS."
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Gala, Kaci Jo. "Design of a new narrow channel apparatus that simulates low gravity conditions for producing near limit flames." Diss., Connect to online resource - MSU authorized users, 2007.
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Choi, Joonho. "Concurrent fire dynamic models and thermomechanical analysis of steel and concrete structures." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26679.
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Overholt, Kristopher J. "Characterizing the Flammability of Storage Commodities Using an Experimentally Determined B-number." Digital WPI, 2009. https://digitalcommons.wpi.edu/etd-theses/1113.
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"In warehouse storage applications, it is important to classify the burning behavior of commodities and rank them according to material flammability for early fire detection and suppression operations. In this study, the large-scale effects of warehouse fires are decoupled into separate processes of heat and mass transfer. As a first step, two nondimensional parameters are shown to govern the physical phenomena at the large-scale, a mass transfer number, and the soot yield of the fuel which controls the radiation observed in the large-scale. In this study, a methodology is developed to obtain a mass-transfer parameter using mass-loss (burning rate) measurements from bench-scale tests. Two fuels are considered, corrugated cardboard and polystyrene. Corrugated cardboard provides a source of flaming combustion in a warehouse and is usually the first item to ignite and sustain flame spread. Polystyrene is typically used as the most hazardous product in large-scale fire testing. A mixed fuel sample (corrugated cardboard backed by polystyrene) was also tested to assess the feasibility of ranking mixed commodities using the bench-scale test method. The nondimensional mass transfer number was then used to model upward flame propagation on 20-30 foot stacks of Class III commodity consisting of paper cups packed in corrugated cardboard boxes on rack-storage. Good agreement was observed between the model and large-scale experiments during the initial stages of fire growth."
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Stalcup, Erik James. "Numerical Modeling of Upward Flame Spread and Burning of Wavy Thin Solids." Case Western Reserve University School of Graduate Studies / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=case1417797653.
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Paudel, Abinash. "Application of One Dimensional Turbulence (ODT) to Model Fire Spread Through Biomass Fuel Bed." BYU ScholarsArchive, 2013. https://scholarsarchive.byu.edu/etd/3988.
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Each year fires destroy millions of acres of woodland, lives, and property, and significantly contribute to air pollution. Increased knowledge of the physics and properties of the flame propagation is necessary to broaden the fundamental understanding and modeling capabilities of fires. Modeling flame propagation in fires is challenging because of the various modes of heat transfer with diverse fuels, multi-scale turbulence, and complex chemical kinetics. Standard physical models of turbulence like RANS and LES have been used to understand the flame behavior, but these models are limited by computational cost and their inability to resolve sub-grid scales. Application of several other models and empirical studies in fire modeling are usually limited to fire spread rate only. In some fires, flame propagation often occurs through convective heating by direct flame contact as opposed to radiative preheating alone. Under these conditions, resolution of the flame front can provide the detailed physics and insights into the flame propagation. The One Dimensional Turbulence (ODT) model is extended to turbulent flame propagation in biomass fuel beds representative of those in wild land fires. ODT is a stochastic model that is computationally affordable and can resolve both large and fine scales. ODT has been widely applied to many reacting and non-reacting flows like jet flames and pool fires. A detailed particle combustion model has been developed and implemented in the ODT model to investigate the fluctuating flame-fuel interface and to study flame propagation properties. The particle reaction is modeled as a single global decomposition reaction model. Radiative, convective, and internal particle conductive heat transfer are included. Gaseous combustion is modeled with a lookup table parameterized by mixture fraction and fractional heat loss using steady laminar flame let solutions. Results are presented from simulations of flame propagation in buoyantly driven flows. Particle size and loading are varied to study their effects in flame spread. A timescale analysis is performed to compare radiative, convective, conductive, and reactive particle time scales to the turbulent fluctuations. The flame propagation in homogeneous turbulence is also studied which better represents the wildland fire. The time scales involved in the wildland fire are overlapped using LEM model to study their effects on the flame properties and flame spread.
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Bland, Kenneth Edward. "Behavior of Wood Exposed to Fire: A Review and Expert Judgement Procedure for Predicting Assembly Failure." Digital WPI, 2005. https://digitalcommons.wpi.edu/etd-theses/1160.
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This paper summarizes research on the structural perfomance of wood elements and assemblies exposed to fire and reviews methodologies available to predict performance. This reasecrh provides a wealth of information on topics such as how fast a flame spreads across the surface of wood, how much smoke is produced during combustion and at what rate does wood char and at what heat release rate.
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Beaulieu, Patricia. "Flammability Characteristics at Heat Fluxes up to 200 kW/m2 and The Effect of Oxygen on Flame Heat Flux." Digital WPI, 2005. https://digitalcommons.wpi.edu/etd-dissertations/427.
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"This dissertation documents two interrelated studies that were conducted to more fundamentally understand the scalability of flame heat flux. The first study used an applied heat flux in the bench scale horizontal orientation which simulates a large scale flame heat flux. The second study used enhanced ambient oxygen to actually increase the bench scale flame heat flux itself. Understanding the scalability of flame heat flux more fully will allow better ignition and combustion models to be developed as well as improved test methods. The key aspect of the first study was the use of real scale applied heat flux up to 200 kW/m2. An unexpected non-linear trend is observed in the typical plotting methods currently used in fire protection engineering for ignition and mass loss flux data for several materials tested. This non-linearity is a true material response. This study shows that viewing ignition as an inert material process is inaccurate at predicting the surface temperature at higher heat fluxes and suggests that decomposition kinetics at the surface and possibly even in-depth may need to be included in an analysis of the process of ignition. This study also shows that viewing burning strictly as a surface process where the decomposition kinetics is lumped into the heat of gasification may be inaccurate and the energy balance is too simplified to represent the physics occurring. The key aspect of the second study was direct experimental measurements of flame heat flux back to the burning surface for 20.9 to 40 % ambient oxygen concentrations. The total flame heat flux in enhanced ambient oxygen does not simulate large scale flame heat flux in the horizontal orientation. The vertical orientation shows that enhanced ambient oxygen increases the flame heat flux more significantly and also increases the measured flame spread velocity."
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Tseng, Ya-Ting. "Three-Dimensional Model of Solid Ignition and Ignition Limit by a Non-Uniformly Distributed Radiant Heat Source." Case Western Reserve University School of Graduate Studies / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=case1307551796.
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Parkes, Anthony Richard. "The impact of size and location of pool fires on compartment fire behaviour." Thesis, University of Canterbury. Civil and Natural Resources Engineering, 2009. http://hdl.handle.net/10092/3444.
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An understanding of compartment fire behaviour is important for fire protection
engineers. For design purposes, whether to use a prescriptive code or performance
based design, life safety and property protection issues are required to be assessed. The
use of design fires in computer modelling is the general method to determine fire safety.
However these computer models are generally limited to the input of one design fire,
with consideration of the complex interaction between fuel packages and the
compartment environment being simplified. Of particular interest is the Heat Release
Rate, HRR, as this is the commonly prescribed design parameter for fire modelling. If
the HRR is not accurate then it can be subsequently argued that the design scenario may
be flawed. Therefore the selection of the most appropriate fire design scenario is
critical, and an increased level of understanding of compartment behaviour is an
invaluable aid to fire engineering assumptions.
This thesis details an experimental study to enhance the understanding of the impact and
interaction that the size and location of pool fires within an enclosure have upon the
compartment fire behaviour. Thirty four experiments were conducted in a reduced scale
compartment (½ height) with dimensions of 3.6m long by 2.4m wide by 1.2m high
using five typical ventilation geometries (fully open, soffit, door, window and small
window). Heptane pool fires were used, located in permutations of three evenly
distributed locations within the compartment (rear, centre and front) as well as larger
equivalent area pans located only in the centre. This thesis describes the experimental
development, setup and results of the experimental study. To assist in the classification
of compartment fire behaviour during the experiments, a ‘phi’ meter was developed to
measure the time dependent equivalence ratio. The phi meter was developed and
configured to measure O₂, CO₂ and CO. The background development, calibration, and
experimental results are reported. A review of compartment fire modelling using Fire
Dynamics Simulator, has also been completed and the results discussed.
The results of this experimental study were found to have significant implications for
Fire Safety Engineering in that the size of the fire is not as significant as the location of
the fire. The effect of a fire near the vent opening was found to have a significant impact
on compartment fire behaviour with the vent located fuel source increasing the total
compartment heat release rate by a factor of 1.7 to that of a centrally placed pool fire of
the same total fuel area. The assumption that a fire located in the centre of the room
provides for the highest heat release rate is not valid for post-flashover compartment
fires. The phi meter was found to provide good agreement with the equivalence ratio
calculated from total compartment mass loss rates, and the results of FDS modelling
indicate that the use of the model in its current form can not be applied to complex pool
fire geometries.
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Neumann, Dorothea. "BRANDSKYDDAT TRÄ : Jämförelse mellan obehandlat, brandskyddsmålat och brandskyddsimpregnerat trä." Thesis, Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-31341.
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Environmental issues and the housing shortage is an ongoing debate among politicians. Wood is a building material that Sweden has plenty of and it is a material that, according to research, does not contribute to as much carbon dioxide emissions during production, compared to other construction materials such as concrete and steel. Therefore the demand for timber, in both facade claddings and external wall constructions, is increasing. In light of this, the purpose with this degree project is to study different fire protection methods for wood and compare it to untreated wood. Collecting the facts and information for this degree project at Mälardalens University, is done through literature studies, surveys, and two experiments conducted on two selected fire retardants. The experiments were conducted to test untreated, fire protection impregnated and wood with fire proof paint. One of the experiments tested the load-carrying capacity of the beams after being charred with a gas burner. The other experiment investigated the surface layer and measured the fire spread rate and both experiments tested the fire resistance. The experiments that were conducted concluded that out of the three different methods for facades and beams, fire protection impregnation was the best choice in all five chosen categories: load-carrying capacity, fire resistance, surfaces, environmental impact and health safety for workers.Miljöfrågan och bostadsbristen är två pågående debatter bland politikerna. Ett byggmaterial som både är miljövänligt och lätt att bygga med är trä. Det är ett byggmaterial som Sverige har gott om och enligt forskning bidrar det inte med lika mycket koldioxidutsläpp vid produktionen jämfört med andra konstruktionsmaterial som betong och stål. Enligt äldre bygglagstiftningar var det enbart tillåtet att bygga hus med två våningar i trä. Det var godkänt att bygga hus med tre våningar om den nedersta våningen bestod utav sten och de två översta i trä. Den nya bygglagstiftningen har inga begränsningar på att använda trä i ytterväggar, oberoende av byggnadsklass så länge de uppfyller funktionskraven. Byggsektorn har varit medveten om att de fick bygga flervåningshus i trä men inte hur det skulle utföras och samtidigt uppfylla bygglagstiftningens krav. Resultatet av ändringarna i bygglagstiftningen, Boverkets byggregler, ökade efterfrågan och utbudet på brandskyddsmedel till trä. De vanligaste produkterna som finns ute för konsumenten är brandskyddsfärg och brandskyddsimpregnering. Trä kan genom brandskyddsimpregnering eller brandskyddsfärg få en brandteknisk klass enligt det europeiska systemet, EN 13501-1, upp mot B-s1,d0 som är högre än för obehandlat trä, Ds1, d0. Tekniskt sett går det att bygga Br1-byggnader med obehandlat trä, dock så krävs det ett antal åtgärder för att uppfylla Boverkets byggreglers funktionskrav, till exempel att installera automatiska släcksystem eller enbart ha trä på en begränsad del av fasaden. Med brandskyddsbehandling går det idag endast att uppnå brandteknisk ytskiktsklass B-s1,d0, vilket inte är tillräckligt enligt Boverkets byggregler som kräver lägst obrännbara fasadbeklädnader i ytskiktsklass A2-s1,d0 för att uppfylla allmänna råden. Fasadbeklädnader av trä, oavsett brandteknisk klass, kan testas med provmetoden SP FIRE 105 och därmed uppfylla föreskriftens krav på ytterväggskonstruktioner med avseende på brandspridning längs fasadytan. Syftet med arbetet är att jämföra olika brandskyddsmetoder av trä och undersöka vilken eller vilka som är bäst lämpad att använda i flervåningshus ur bland annat miljö-, arbetsmiljö- och brandsynpunkt. Detta uppnås genom en litteraturstudie som fokuserar på ämnet brandskyddsmetoder av trä och genom två försök genomfördes för att testa obehandlat, brandskyddsimpregnerat och brandskyddsmålat trä. Ett försök testade bärförmågan efter brandpåverkan, andra undersökte ytskikt, och båda försöken testade brandmotstånd. Bärförmågan testades genom att brandpåverkade reglar blev utsatta för en central punktlast i en Instron- maskin. Ytskikten prövades genom ett enklare försök baserad på testmetoden SP FIRE 105 på tre fasader. En obehandlad, en brandskyddsimpregnerad och en brandskyddsmålad. Mätningar och dokumentation gjordes med bland annat mätinstrument som plattermoelement och filmkamera. Båda typerna av brandskyddsmetoder kräver en kemisk framställning som varken är bra för naturen eller människan. Produktionen är automatiserad och därmed inte någon risk för någon människa. Den färdiga produkten är varken skadlig för miljön, människor eller djur, sålänge inte produkterna förtärs i större omfattning. Resultatet från undersökningen av de tre olika fasaderna visade att det brandskyddsimpregnerade virket klarade sig bäst i alla fem kategorier: bärförmåga, brandmotstånd, ytskikt, miljöpåverkan och arbetsmiljö. Slutsatsen är av det två typer av brandsskyddsmedel för trä som testades, är brandskyddsimpregnering den mest lönsammaste alla fem kategorier. Produkten är lätthanterad, avger inga farliga gaser och är i snitt inte dyrare än det obehandlade materialet. Dock är det viktigt att tänka på brandskyddsarbete och inte släppa på säkerheten för att konstruktionen byggs med brandskyddsimpregnerat trä.
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Horvath, Istva'n. "Extreme PIV Applications: Simultaneous and Instantaneous Velocity and Concentration Measurements on Model and Real Scale Car Park Fire Scenarios." Doctoral thesis, Universite Libre de Bruxelles, 2012. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209641.
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This study is a presentation of an instantaneous and simultaneous velocity and concentration measurement technique and its applications on car park fire scenarios. In this actual chapter 1 general introduction is given to each chapter. Chapter 2 is dedicated to a detailed description of the instantaneous and simultaneous velocity and concentration measurement technique and its associated error assessment methodology. The name of the new technique is derived from the names of the acquired parameters (VELocity and COncentration) and shall be hereafter referred to as VELCO. After having validated and performed an error assessment of this technique, it is applied to an investigation of full-scale car park (30 m x 30 m x 2.6 m – Gent / WFRGENT) fire cases in chapter 3. The measurements were carried out with the financial support of IWT-SBO program. In the full-scale measurements only the velocity part is applied of VELCO, yet it can be considered as its application since the special data treating was developed and implemented in the Rabon (see: §2.1.2) program, which is the software of the new technique along with Tucsok (see: §2.1.1) and they will be both discussed in the related chapter. Here it is enough to mention that the concentration and velocity information can be obtained independently as well. During the full-scale measurements, beyond of VELCO the smoke back-layering distances (SBL) are also derived from the temperature values, which were measured by thermocouples under the ceiling in the midline of the car park. The critical velocity, which is an important measure of fire safety, can be obtained from the SBL results. In chapter 4, isothermal fire modeling is surveyed in order to present how full-scale fires are modeled in small-scale. In this part of the study the theory of fire related formulae and an isothermal model are described. Here it is important to stress the fact that the fire modeling is not directly related to the VELCO technique. However it connects the full-scale to the small-scale measurements, which the technique is applied on. Chapter 5 discusses small-scale measurements (1:25 – Rhode Saint Genese / VKI) on the car park introduced in chapter 3 and their validation. After the validation, more complex car parks scenarios are also investigated due to the easy to change layout in the small-scale model with respect to the full-scale car park. In this chapter the smoke back-layering distances are obtained by VELCO. Finally, in chapter 6 important conclusions are drawn with the objective of increasing fire safety.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished
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Zhang, Jianping. "Numerical modelling of pool fires and flame spread." Thesis, Kingston University, 2005. http://eprints.kingston.ac.uk/20319/.
Full textAbstract:
A historical analysis by Planas-Cuchi ‘et al’. showed that pool fires are one of the most frequent fire accidents in family homes, in the processing industries and in the transport of hazardous substances. Experimental and theoretical studies of the turbulence structure, fluid mechanics and heat transfer in pool fires, therefore, are of great importance for fire engineers to the understanding of the inherent mechanisms in pool fires. To this end, the first objective of this study is to investigate pool fires and improve their modelling by means of the computational fluid dynamics (CFD) approach, in which coupled descriptions of the controlling mechanisms of heat transfer, turbulence, combustion, and soot production are included. In order to improve the accuracy and applicability of existing turbulence and gas radiation models, advanced models including a four-equation turbulence model, a statistical narrow band (SNB) gas radiation model and a correlated-k (CK) gas radiation model are developed and implemented into the CFD code simulation of fires in enclosures (SOFIE) as the first step of this PhD study. The modified code is applied to three pool fire scenarios, i.e. methane, methanol and ethanol pool fires. Simulation results are numerically analysed, and quantitatively compared between the predictions obtained with different models, as well as with experimental data. Results confirm the improvements in accuracy from advanced models-in terms of temperature predictions, up to 59% relative difference for the four-equation turbulence model and 8.8% for the SNB models are found, though more CPU time is required - the four-equation model requires about 10% more than the two-equation models investigated and the SNB model requires 4.8 times of the traditional weighted-sum-of-grey-gas (WSGG) model. As shown in the Methane fire simulations, the CK model yields results very close to the SNB model, while 2.7 times more time consuming, and thus the CK model is not further studied in this work. After the analysis of pool fires mechanisms and validation of the incorporated models, this research is focused on the numerical and experimental investigation of upward flame spread over solid fuel surfaces. A non-charring pyrolysis model has been developed in SOFIE and is used in this study. A formulation of Quintiere is implemented and employed for predicting the flame spread rate. The pyrolysis model coupled with the filed model is employed to simulate an upward flame spread experiment conducted as part of this work by the author’s research group. In the experiment, temperature, gas velocity, and radiative heat fluxes are measured respectively with thermocouples, particle-image-velocimetry (PIV) and Gunner's radiometers. CFD predictions for surface heat fluxes, the gas velocity, surface temperatures, the flame spread rate, the mass burning rate and the heat release rate are evaluated. The simulation results are generally in good agreement with the experiment. The last objective is to assess the effect of gas radiation models on upward flame spread simulations. Further predictions are attempted for two, more complex flame spread configurations, one involving a 5mX0.6m polymethylmethacrylate (PMMA) wall while the other representing flame spread along the corner. Quantitative and qualitative comparisons are made between the predictions and experimental data. Significant improvement is made by the SNB model over the WSGG model. Although the WSGG approach yields relatively closer results to the SNB approach for the simulations of the steady problem - pool fires, it produces larger discrepancies for those of the transient problem - flame spread, in which the accurate predictions of combined surface heat fluxes are of particular importance.
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Chun-YuHuang and 黃俊諭. "Analysis on Fire Resistance of Curtain Wall System and Flame Spread of Building Exterior Wall." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/r55vag.
Full textAbstract:
碩士國立成功大學
機械工程學系
107
The fire resistance performance of curtain wall systems played a crucial role in preventing loss in property and human life, especially in high rise fires. When a fire occurs, it will spread to the room above in two ways: propagating on the exterior wall surface of the wall, and penetrating through a joint between a vertical wall and the floor slab. Perimeter joint protection serves a fire barrier to preventing fire from spreading. In exterior thermal insulation system, combustible thermal insulation material lead to potential fire risk. In this study, a full scale fire resistance performance test of a curtain wall system and a reduced scale flame spread test of thermal insulation material were conducted. A commercial stick system aluminum curtain wall system was tested. The specimen’s fire resistance was determined to be 58 minutes and 40 seconds based on the T-rating, and 1 hour and 40 minutes based on the F-rating. After 1 hour and 40 minutes, the gas flow rate exceeded the limit, so the test result could not be analyzed. Compared with previous test, the design of the test specimen was modified and a gas barrier was added. The fire resistance of the test specimen was found to be enhanced. In tests with thermal insulation materials, 5 polystyrene products and 4 polyurethane were tested with cone calorimeter first. The results showed that only PU_1 met the requirements for inflammability grade 1. Other products could not met the requirements for inflammability grade 3. 2 polystyrene and 2 polyurethane products were tested in the flame spread test. The results showed that, melted polystyrene products can lead to the downward flame spread and to intensification of a fire. In the tests with PU_1, no flame spread phenomenon was observed. In the test with PU3, after being ignited, PU3 burned steadily, spread upward and posed a danger to the upper floor.
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(8081456), Vikrant E. Goyal. "Investigation of Fire Safety Characteristics of Alternative Aviation Fuels." Thesis, 2019.
Find full textAbstract:
Due to the depletion of fossil fuel reserves and emission challenges associated with its usage, there is a need for alternative aviation fuels for future propulsion. The alternative fuels with handling, storage and combustion characteristics similar to conventional fuels can be used as “drop-in” fuels without significant changes to the existing aviation infrastructure. Fire safety characteristics of alternative aviation fuels have not been studied intensively and therefore research is needed to understand these characteristics. In this study, fire safety characteristics namely hot surface ignition (HSI) and flame spread phenomena are investigated for alternative aviation fuels.
HSI is defined as the process of a flammable liquid coming in contact with a hot surface and evaporating, mixing and reacting with the surrounding oxidizer with self-supporting heat release (combustion). If all the conditions are adequate, the fuel may completely turn into combustion products following the ignition process. This work presents results from more than 5000 ignition tests using a newly developed reproducible test apparatus. A uniform surface temperature stainless steel plate simulating the wall of a typical exhaust manifold of an aircraft engine is used as the hot surface. Ignition tests confirmed that the ignition event is transient and initiates at randomly distributed locations on the hot surface. The results show many significant differences and some similarities in the ignition characteristics and temperatures of the different fuels. In this work, hot surface ignition temperatures (HSITs) are measured for nine hydrocarbon liquids. Five of these fuels are piston engine based, three fuels are turbine-engine based and one fuel is a pure liquid, heptane. The piston engine based fuels are given by FAA and are confidential and hence labeled as test fuels A, B, C, D for this study. The HSITs of these fuels are measured and compared against a baseline fuel 100 LL aviation gasoline (100LL Avgas). HSITs of conventional turbine engine based fuels namely Jet-A, JP-8, and JP-5 are also measured.
Flame spread along liquid fuel has been one of the important combustion phenomena that still requires more in-depth research and analysis for the deep understanding of the chemical processes involved. Flame spread rate determines how fast the flame spreads along the fuel surface and it is an important parameter to study for fire safety purposes. For the flame spread rates study, a novel experimental apparatus is designed and fabricated. The experimental apparatus consists of a rectangular pan, a fuel heating system, an autonomous lid actuation system, a CO2 fire extinguisher system, and a laser ignition system. The flame spread phenomenon is studied for a conventional aviation fuel namely, Jet-A and three alternative aviation fuels namely, hydro-processed ester fatty acids (HEFA-50), Fischer-Tropsch – IPK (FT-IPK) and synthetic iso-paraffin (SIP). The experiments are conducted for a wide range of initial fuel temperatures ranging from 25°-100°C for Jet-A, HEFA-50, FT-IPK and from 80-140°C for SIP as the flash-point of SIP is 110°C and is ~3 times higher than that of other three fuels. The flame spread rate of all fuels increases exponentially with increasing fuel’s initial temperature. Flame spread rate is as low as ~5 cm/sec for Jet-A, HEFA-50, FT-IPK for 25°C initial fuel temperature and goes to as high as 160 cm/sec for 80°C initial fuel temperature. For SIP based jet fuel, flame spread rate is ~160 cm/sec for initial fuel temperature of 140°C. Additionally, it was also found that the flame propagation consists of two types of flames: a precursor blue flame located ahead of the main yellow flame. These flames are more evident over the fuels’ surface with initial fuel temperatures higher than their respective flash-points. The precursor blue flame propagates like a premixed flame and the main yellow flame propagates like diffusion combustion.
This dissertation includes eight chapters. Chapter 1 gives an overview
of the work done until now in the field of hot surface ignition. Following this
review, the experimental apparatus designed and fabricated for this study are
discussed in Chapter 2. This chapter also talks about the test matrix, data
acquisition tools and concludes with the data analysis method. In Chapter-3,
HSITs of 3 turbine engine based fuels and 5 piston engine based fuels are
reported. This chapter also discusses the effect of drop height and curvature
(flat v/s cylindrical) for two fuels, Jet-A, and heptane. This concludes the
work done in the field of HSI in this dissertation. Chapter 4 talks about the
past work reported by various researchers in the field of flame spread
phenomenon and key learnings from their work. Chapter 5 discusses the
experimental apparatus designed and fabricated for flame spread phenomenon
study. In chapter-6, flame spread rates of 4 alternative aviation fuels are
reported. This chapter also discusses the flame spread mechanism associated
with slower (liquid-phase controlled) and faster (gas-phase controlled) flame
propagation. Chapter 7 discusses flame propagation which consists two types of
flames: a precursor blue flame and a main yellow flame. Chapter 8 concludes the
key findings of the hot surface ignition and flame spread phenomenon study in this
research work
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Comitis, Spiros Costas. "An experimental and modelling study of fires in ventilated passages." Thesis, 1994. http://hdl.handle.net/10539/22932.
Full textAbstract:
A thesis submitted to the Faculty of Engineering, University of
the Witwatersrand, Johannesburg, in fulfillment of the
requirements for the degree of Doctor of Philosophy.A theoretical and experimental treatment of fire processes in fuel-Lined, ventilated passages is presented. Initially a radially well mixed axial flow condition is considered. Experiments are first performed in non-stratified flow conditions where fire propagation and gas temperature histories are acquired from liquid and solid fuelled fires. Theory and experiment;display transient fire propagation for typical duct fire scenarios where initial fuel mass Loading is constant with respect to duct length. ( Abbreviation abstract )
AC2017
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Didomizio, Matthew. "On the Potential Use of Small Scale Fire Tests for Screening Steiner Tunnel Results for Spray Foam Insulation." Thesis, 2013. http://hdl.handle.net/10012/7530.
Full textAbstract:
The goal of this study is to assess the potential of using bench-scale fire testing to screen materials for the Steiner tunnel fire test. It is hypothesized that the chemical and physical changes made to a material to improve its fire performance in small scale fire tests will have a predictable response in the Steiner tunnel. This hypothesis is based on the observation that fire test results can, in some cases, provide insight on a material's relative fire hazard, and the assumption that the relative hazard should be consistent across scale.
The ASTM E84 Steiner tunnel test provides a relative ranking of material hazard in two categories. The horizontal Flame Spread Index (FSI) is used to rank the flame hazard of a material, and the Smoke Developed Index (SDI) is used to rank the smoke hazard of a material. Two fire tests are proposed to independently assess each hazard at the bench-scale. The ASTM E1354 cone calorimeter test measures a material's open-flaming heat release rate; it is proposed that the cone calorimeter test can be used to assess a material's relative flame hazard. The ISO 5659-2 smoke density chamber test measures a material's closed-environment smoke development; it is proposed that the smoke density chamber test can be used to assess a material's relative smoke hazard.
The material selected for this study is fire-retarded sprayed polyurethane foam (FRSPF) insulation. Specific details of the foam chemistry, fire retardants, and the manufacturer are confidential. Generally, the foam can be described as medium-density (approximately 2 lbs/ft³), closed-celled, and semi-rigid. The fire retardant additives are comprised of differing ratios and concentrations of phosphorous- and halogen-containing compounds.
A series of 30 Steiner tunnel tests is conducted on 20 different formulations. Repeated testing is conducted on several formulations in order to assess variability in the Steiner tunnel test results. Cone calorimeter and smoke density chamber tests are conducted on a subset of those formulations, in sets of 3-5 tests per formulation.
Key performance indicators are identified from each fire test, relationships between those indicators are examined, and correlations are presented where strong relationships are apparent. Empirical prediction models are proposed for FSI and SDI based on the success rate of prediction, and minimization of error between experimental (measured) and modelled (predicted) results. It is concluded that for the materials tested in this study, there is sufficient evidence of consistency in relative performance to recommend bench-scale screening tests as a cost-effective alternative to repeated Steiner tunnel testing.
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Anderson, Stuart A. J. "Fuel moisture and development of ignition and fire spread thresholds in gorse (Ulex europaeus) : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Forestry Science in the University of Canterbury /." 2009. http://hdl.handle.net/10092/3013.
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Prine, Brenda. "A Methodology for Global Comparison of Fire Testing Standards in Transportation Applications." Thesis, 2013. http://hdl.handle.net/10012/7893.
Full textAbstract:
In recent decades, many manufacturing industries have globalized their operations and the Canadian manufacturing sector has experienced dramatic downsizing. For a manufacturing company to succeed therefore, it is necessary for them to operate with a global perspective. In the area of fire safety, this requires understanding of, and compliance with, global regulatory requirements.
This research develops a systematic approach that can be utilized to analyze and compare the complex fire safety regulatory requirements that are stipulated for a selected topic in various countries. The approach developed is sufficiently general that it can be leveraged to compare and contrast global standards in any field or discipline. The methodology outlines six aspects of the regulatory environment that must be considered in sorting standards and then uses spreadsheets and a mind mapping program to elucidate the many relationships that exist amongst the current standards.
In this work, flammability test requirements for public transportation seating are studied, with a major emphasis on seating for railway applications. Requirements for seating in aviation, automotive (both cars and buses) and military vehicles are included in the discussion for comparative purposes.
Fire is a complex phenomenon that is difficult to characterize. The legislated testing protocols reflect this complexity with some geographic jurisdictions mandating as many as six different types of fire testing for rail seating. This work looks in depth at two of the main types of fire testing: flame spread testing and toxic effluent testing.
Flame spread testing was chosen because it is widely required, and toxic effluent testing was chosen because of the many complexities and ambiguities present amongst these standards. Eleven flame-spread tests are compared on a semi-quantitative basis, and eight fire effluent toxicity tests are discussed on a qualitative basis.
The technique developed was useful to elucidate the relationships, similarities and differences amongst the fire safety requirements for transportation seating. There are large differences in requirements among transportation sectors as well as on a geographical basis. Using this technique, it was possible to categorize the flame spread tests into two groups and to compare the relative intensity of the tests within each of these subsets. The fire effluent toxicity tests varied so much in approach that only qualitative comparisons were possible.