Fire Protection Engineering Theses and Dissertations
Permanent URI for this collectionhttp://hdl.handle.net/1903/2772
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Item EVALUATION OF IMPACT OF NOVEL BARRIER COATINGS ON FLAMMABILITY OF A STRUCTURAL AEROSPACE COMPOSITE THROUGH EXPERIMENTS AND MODELING(2021) Crofton, Lucas; Stoliarov, Stanislav; Fire Protection Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Composites have become a integral part of the structure of airplanes, and their use within aircraft continues to grow as composites continue to improve. While polymer composites are an improvement in many facets to traditional airspace materials, their flammability is something called into question. The work performed for this study was to create a pyrolysis model for a particular aerospace composite, IM7 graphite fiber with Cytec 5250-4 Bismaleimide matrix (BMI), and three innovative composite barrier coatings that could be applied to the BMI to potentially improve its performance in fire scenarios. The composites were all tested individually, in a series of milligram-scale tests, and the test results were inversely analyzed to determine stoichiometry, chemical kinetics, and thermodynamics of their thermal decomposition and combustion. Gram-scale experiments using the Controlled Atmosphere Pyrolysis Apparatus II (CAPA II) were performed on the BMI by itself and then again with one of each of the composite barrier coatings applied in a defined thickness. This data were inversely analyzed to define the thermal conductivity of the sample and resolve it’s emissivity. It was found after fully defining a pyrolysis model for each composite material that the composite barrier coatings did not provide any benefit to the base composite BMI, and only added more fuel load which in turn contributed to a increase in heat release rate when computational simulations were run to mimic a airplane fuel fire.Item Pyrolysis of Reinforced Polymer Composites: Parameterizing a Model for Multiple Compositions(2015) Martin, Geraldine Ellen; Stoliarov, Stanislav I; Fire Protection Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)A single set of material properties was developed to describe the pyrolysis of fiberglass reinforced polyester composites at multiple composition ratios. Milligram-scale testing was performed on the unsaturated polyester (UP) resin using thermogravimetric analysis (TGA) coupled with differential scanning calorimetry (DSC) to establish and characterize an effective semi-global reaction mechanism, of three consecutive first-order reactions. Radiation-driven gasification experiments were conducted on UP resin and the fiberglass composites at compositions ranging from 41 to 54 wt% resin at external heat fluxes from 30 to 70 kW m-2. The back surface temperature was recorded with an infrared camera and used as the target for inverse analysis to determine the thermal conductivity of the systematically isolated constituent species. Manual iterations were performed in a comprehensive pyrolysis model, ThermaKin. The complete set of properties was validated for the ability to reproduce the mass loss rate during gasification testing.Item A Model for Non-Oxidative and Oxidative Pyrolysis of Corrugated Cardboard(2013) Semmes, Molllie Rose; Stoliarov, Stanislav I; Fire Protection Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Corrugated cardboard is widely used in warehouse facilities. The flammable nature of the material, coupled with its ubiquitous presence makes the material a serious fire hazard. As a result, there is interest in developing a universal pyrolysis model that can accurately predict the burning characteristics of the cardboard. Pyrolysis of a double-wall corrugated cardboard was studied in anaerobic and oxygen containing atmospheres using thermogravimetric analysis and a newly developed Controlled Atmosphere Pyrolysis Apparatus (CAPA). The effects of moisture were also examined under non-oxidative conditions. A previously developed cardboard pyrolysis model was demonstrated to reproduce anaerobic gasification. This model was extended to include oxygen diffusion, oxidation reactions, and modified evaporation reactions. The modified model was validated against the mass loss rate data collected in the CAPA at 10.5 vol.% of oxygen and at 2.2 vol.% oxygen with moisturized samples under incident radiant heat fluxes of 20, 40, and 60 kW m-2.Item NUMERICAL MODELING OF BALCONY SPILL PLUMES USING FIRE DYNAMICS SIMULATOR (FDS)(2010) Lim, Johnson Meng Kee; Trouvé, Arnaud C; Fire Protection Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Trends in modern architectural design have led to the proliferation of large atrium buildings. Fires in such buildings can result in significant loss of life and property damage as the propagation of smoke is unimpeded. The design of effective smoke management systems for atrium buildings requires reliable calculation methods to predict the quantity of smoke produced. Numerical modeling using FDS is performed in this research to examine the entrainment processes as the smoke flows from a compartment, through a balcony before discharging into an atrium. Different fire sizes and geometrical configurations are analyzed and empirical correlations are proposed for the mass flow rate of smoke at the spill edge and for the entrainment as the smoke rotates upwards around the spill edge. These correlations show good agreement with experimental data from previous work.Item SCALE MODELING OF STATIC FIRES IN A COMPLEX GEOMETRY FOR FORENSIC FIRE APPLICATIONS(2010) Carey, Allison Charlotte; Quintiere, James G; Fire Protection Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Scale modeling can allow fire investigators to replicate specific fire dynamics at a dramatically reduced cost. A gas burner, liquid pool, wood crib, and polyurethane foam block are used to represent the wide range of fuels that investigators encounter. These fuels are classified into two groups: the burner and liquid pool that reach a semi-immediate steady state (static fires) and the crib and foam that have a fire spread and growth period (dynamic fires). This research examines the proposed scaling method for the static fires. The enclosure consists of a large corridor that provides an interesting challenge due to the presence of partitions at the ceiling. The design fires and the model enclosure are designed based on Froude scaling derived from conservation equations. The eight various sized fires demonstrate acceptable scaling results in the prediction of flame height and temperature at various elevations in the enclosure.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.