Flexible polyurethane foam (PUF) is a very versatile material ever created. The material is used for various applications and consumer end-use products such as upholstered furniture and mattresses. The increased use of these polymeric materials causes fire safety concerns. This has led to the development of various regulations and flammability test standards aimed at addressing the hazards associated with polyurethane foam fires. Several fire protection engineering correlations and thermal models have also been developed for the simulation of fire growth behaviour of polyurethane foams. Thus, the overall objective of this research project is to investigate the laboratory test behaviour of this material and then use finer modeling techniques to predict the heat release rate of the specimens, based on information obtained from cone calorimeter tests.<p> Full-scale fire tests of 10 cm thick polyurethane foams of different sizes were conducted using center and edge-ignition locations. Flame spread and heat release rates were compared. For specimens of the same size, center-ignition tests produced flame areas and peak heat release rates which were respectively 10 and 20% larger compared to edge-ignition tests. Average flame spread rates for horizontal and vertical spread were determined, and results showed excellent agreement with literature. Cone calorimeter tests of the specimens were performed using steel edge frame and open durarock board. Results indicate that different test arrangements and heat sources have significant effects on the fire behaviour of the specimens.<p> Predictions using the integral convolution model and other fire protection engineering correlations were compared with the full-scale tests results. Results show that the model was more efficient in predicting the heat release rates for edge-ignition tests than the center-ignition tests. The model also was more successful in predicting the heat release rates during the early part of the growth phase than during the later stages of the fire. The predicted and measured peak heat release rates and total heat release were within 10-15% of one another. Flame spread and t-squared fire models also gave satisfactory predictions of the full-scale fire behaviour of the specimens.

Flexible polyurethane foam (PUF) is a very versatile material ever created. The material is used for various applications and consumer end-use products such as upholstered furniture and mattresses. The increased use of these polymeric materials causes fire safety concerns. This has led to the development of various regulations and flammability test standards aimed at addressing the hazards associated with polyurethane foam fires. Several fire protection engineering correlations and thermal models have also been developed for the simulation of fire growth behaviour of polyurethane foams. Thus, the overall objective of this research project is to investigate the laboratory test behaviour of this material and then use finer modeling techniques to predict the heat release rate of the specimens, based on information obtained from cone calorimeter tests.<p> Full-scale fire tests of 10 cm thick polyurethane foams of different sizes were conducted using center and edge-ignition locations. Flame spread and heat release rates were compared. For specimens of the same size, center-ignition tests produced flame areas and peak heat release rates which were respectively 10 and 20% larger compared to edge-ignition tests. Average flame spread rates for horizontal and vertical spread were determined, and results showed excellent agreement with literature. Cone calorimeter tests of the specimens were performed using steel edge frame and open durarock board. Results indicate that different test arrangements and heat sources have significant effects on the fire behaviour of the specimens.<p> Predictions using the integral convolution model and other fire protection engineering correlations were compared with the full-scale tests results. Results show that the model was more efficient in predicting the heat release rates for edge-ignition tests than the center-ignition tests. The model also was more successful in predicting the heat release rates during the early part of the growth phase than during the later stages of the fire. The predicted and measured peak heat release rates and total heat release were within 10-15% of one another. Flame spread and t-squared fire models also gave satisfactory predictions of the full-scale fire behaviour of the specimens.

<div>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. </div><div><br></div><div>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. </div><div><br></div><div>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.</div><div><br></div><div>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 </div><div><br></div>

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.

"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."