Fire Protection Engineering Theses and Dissertations
Permanent URI for this collectionhttp://hdl.handle.net/1903/2772
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Item Simulating the Fuel Mass Loss Rate in Fire Dynamics Simulator (FDS) Using a New Furniture Calorimeter(2010) McKeever, Meghan Allison; Trouve, Arnaud; Fire Protection Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Fire Dynamics Simulator (FDS) is widely used in the fire community to simulate and understand in detail enclosure fire dynamics. Fire models require accurate descriptions of the fuel sources to simulate the fire behavior. One approach in FDS is to describe the fuel mass loss rate from furniture calorimeter tests. Unfortunately furniture calorimeter tests do not account for enclosure effects on the fuel sources (i.e. the thermal feedback of the smoke layer and the air vitiation). This work explores a simple pyrolysis model that uses furniture calorimeter data and applies a correction to the data to represent enclosure effects. The study includes: (1) the development of a database which compiles furniture calorimeter data, (2) the development of a modified version of FDS that incorporates a simple pyrolysis model proposed by Professor Quintiere and (3) a performance evaluation of the model by detailed comparisons between FDS results and experimental data from two studies performed at the University of Canterbury.Item EVALUATION OF THE THERMAL PERFORMANCE OF FIRE FIGHTER PROTECTIVE CLOTHING WITH THE ADDITION OF PHASE CHANGE MATERIAL(2010) McCarthy, Lee K.; di Marzo, Marino; Fire Protection Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Fire fighters rely on fire fighter protective clothing (FFPC) to provide adequate protection in the various hazardous environments they may encounter during operations. FFPC has seen significant advancement in technology over the past few decades. The addition of phase change material (PCM) to FFPC is a new technology with potential to enhance the thermal protection provided by the FFPC. To explore this technology, data from bench-scale experiments involving FFPC with PCMs are compared with a theoretical finite difference heat transfer model. The results demonstrate an effective method to mathematically model the heat transfer and provide insight into the effectiveness of improving the thermal protection of FFPC. The experiments confirm that the latent heat absorbed during the phase change reduces temperatures that might be experienced at the fire fighter's skin surface, advancing the high temperature performance of FFPC.Item PYROLYSIS MODEL PARAMETER OPTIMIZATION USING A CUSTOMIZED STOCHASTIC HILL-CLIMBER ALGORITHM AND BENCH SCALE FIRE TEST DATA(2009) Webster, Robert Dale; Trouvé, Arnaud C; Fire Protection Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This study examines the ability of a stochastic hill-climber algorithm to develop an input parameter set to a finite difference one-dimensional model of transient conduction with pyrolysis to match experimentally determined mass loss rates of three sample materials exposed to a range of constant incident heat flux. The results of the stochastic hill-climber algorithm developed as part of the present study are compared to results obtained with genetic algorithms. Graphical documentation of the impact of single parameter mutation is provided. Critical analysis of the physical meaning of parameter sets, and their realistic range of application, is presented. Criteria are also suggested for stability and resolution of solid phase temperature and fuel mass loss rate in an implicit Crank-Nicolson scheme with explicit treatment of the heat generation source term.Item Quenching Limits and Materials Degradation of Hydrogen Diffusion Flames(2008-04-25) Morton, Nicholas Ryan; Sunderland, Peter B; Fire Protection Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This study examines the types of hydrogen leaks that can support combustion and the effects on various materials of long term hydrogen flame exposure. Experimental and analytical work is presented. Measurements included limits of quenching, blowoff, and pilted ignition for burners with diameters of 0.36 to 1.78 mm. Flow rates of 0.019 to 40 mg/s for hydrogen, 0.12 to 64 mg/s for methane, and 0.03 to 220 mg/s for propane were studied. Materials degradation experiments were conducted on carbon steel, stainless steel, aluminum alloy, and carbon fiber. Noticeable corrosion is present on 304 and 316 stainless steel, galvanized 1006 - 1008 carbon steel. Silicon carbide fibers perform relatively similarly for hydrogen and methane flame exposure.Item An Assessment of the Use of Flame Retardant Plastics for Museum Applications(2007-12-18) Leikach, Danielle Caryn; Mowrer, Frederick; Brostoff, Lynn; Fire Protection Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Halogenated flame retardant plastic sheeting may help to reduce flame spread in museums; however, the plastics contain chemicals that may be harmful to museum objects in situ, particularly metals. This study assesses historical and contemporary problems and benefits associated with flame retardant plastics with respect to museum applications. This issue was addressed by pairing statistical data on museum fires with standard and novel methods for assessing corrosivity, while also creating a format for future assessments of fire-safety related practices as they are applied in museum settings. Flame retardant plastics were found to cause small rates of corrosion in copper, approximately 1.2 milli-inches per year (mpy), compared to pure polyethylene which corrodes at approximately 0.83 mpy. Conventional testing methods show that flame retardant plastics can be considered safe for limited museum use and that they delay ignition from small heat sources, but they must be assessed for each individual scenario.Item A Methodology for Flammability Diagrams(2004-12-09) Panagiotou, Joseph; Quintiere, James G; Fire Protection Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The current state of fire safety regulations in the United States Department of Transportation is examined, along with some of the associated flammability test methods. The applicability and overall usefulness of these tests is evaluated along with their ability to accurately capture and describe fire performance. Theoretical relationships are shown for the fire phenomena ignition, energy release and flame spread in terms of incident flux to demonstrate the ability to extract meaningful data from calorimetry and flame spread tests. This is done for sample materials to obtain a general overview of their fire performance. This general overview is presented in the form of a Flammability Diagram. A Flammability Diagram is a single plot showing the energy release rate, time to ignition and flame spread rates for a material all as a function of the incident heat flux. Effects of melting, dripping, thickness, sooting and other factors may not be fully described, but the experimental framework captures the overall result of such effects. This study shows the feasibility of developing a measurement methodology that can be followed for the creation of Flammability Diagrams, providing a clear picture of a material's fire performance.