Fire Protection Engineering
Permanent URI for this communityhttp://hdl.handle.net/1903/2241
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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 The Impact of Thermal Imaging Camera Display Quality on Fire Fighter Task Performance(2008) Rowe, Justin Lawrence; Mowrer, Frederick W.; Fire Protection Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Thermal imaging cameras (TIC) have become a vital fire fighting tool for the first responder community but there are currently no standardized quality control regulations. The purpose of the study was to understand the impact of TIC display image quality on a fire fighter's ability to perform a hazard recognition task. Test subjects were asked to identify a fire hazard by observing infrared images. The image matrix considered the interactions of several image characteristics including contrast, brightness, spatial resolution, and noise. The results were used to create a model function to predict the effect of image quality on user performance. This model was recommended to be incorporated in image quality test methods in development at the National Institute of Standards and Technology. These recommendations will also be provided to the National Fire Protection Association for use in an upcoming standard on fire fighting TIC.Item Numerical modeling of full scale limited ventilation fire tests(2008) Boehmer, Haavard; Trouvé, Arnaud; Fire Protection Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Underventilated enclosure fires represent one of the largest causes of fire fatalities and understanding their behavior is of great interest. The newest major release of the Fire Dynamics Simulator (FDS) has made significant progress towards providing a tool for accurate modeling of underventilated fire behavior. This study sought to evaluate the effectiveness of the extinction model and two-step combustion model in FDS version 5 by simulating full scale fire tests in an apartment setting with realistic furniture items using heat release rate data from furniture calorimeter and load cell. The extinction model provides a more accurate representation of the fire behavior in the compartment but the oxygen and temperature results are not satisfactory for severely underventilated fires. The effects of the enclosure causes heat release rate data from free-burn calorimeter tests to give a poor representation of the burning behavior of real furniture items in a compartment.Item Fire Safety of Today's and Tomorrow's Vehicles(2008-05-02) Levy, Kevin Martin; Sunderland, Peter B; Milke, James A; Fire Protection Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This thesis considers fire hazards in the existing vehicle fleet and uses failure modes and effects analyses of three generic designs to identify and rank potential fire hazards in the Emerging Fuel Vehicle (EFV) fleet. A statistics based predictive quantitative risk assessment framework and estimated uncertainty analysis is presented to predict risk of EFV fleets. The analysis also determines that the frequency of fire occurrence is the greatest factor that contributes to risk of death in fire. These preliminary results predict 420±14 fire related deaths per year for a fleet composed entirely of gasoline-electric hybrid vehicles, 910±340 for compressed natural gas vehicles, and 1300±570 for hydrogen fuel-cell vehicles relative to the statistical record of 350 for traditional fuel vehicles. The results are intended to provide vital fire safety information to the traveling public as well as to emergency response personnel to increase safety when responding to EFV fire hazards.