ICSE Research - Institute for Clean and Secure Energy

Fires and Explosions

Uncontrolled fires result in more than 3000 deaths and $10 billion in property damages per year. Emissions from these fires, as well as controlled fires for agriculture and forest management, contribute significantly to atmospheric organic particulate pollution, which in turn creates a health threat, impacts visibility, and contributes to global warming through the increased absorption of solar radiation. ICSE seeks to improve understanding of fires and explosions by combining tools for fire simulation, experiments, and analysis.

Fire Simulations

ICSE researchers perform fire simulations using a high fidelity fire model that spans the range of length and time scales from that characterize the fire physics in large diameter fires (> 1m). These scales range from chemical kinetics O(gigaseconds) at the molecular level to convective mixing O(1s) in the turbulent flow of the fire. Our fire model uses Large Eddy Simulation (LES) to resolve the large length and time scales that control the dynamics of the fire while the smaller, more universal scales are modeled. We couple LES with models for combustion chemistry, radiative heat transfer, and soot formation and destruction to solve problems ranging from design of large-scale fire experiments to developing protocols involving a bonfire test for transportation classification of hazardous materials. Within the C-SAFE program, ICSE researchers are working to predict the potential hazard of an explosive device immersed in a pool fire of transportation fuel by computing heat flux to the surface of the container.

Key personnel: Philip Smith, Jennifer Spinti, and Jeremy Thornock

Fire Model

Our methodology for achieving predictability in fire simulations is to make decisions on algorithms and components based on a foundation of Verification and Validation (V&V). Verification quantifies the numerical accuracy of a code by comparison with known solutions. Validation assesses the modeling accuracy of a simulation by comparison with experimental data.

The V&V hierarchy of a computational code is based on the intended use of the simulation and is composed of several levels of decreasing technical complexity: the full system or intended use of the model, subsystem cases, benchmark cases, coupled problems, unit level problems, and molecular processes. As one goes down the hierarchy, the amount of data available for comparison increases and the experimental uncertainties decrease. Each box in the hierarchy represents a data set or group of data sets that apply to the case identified by the label on the box.

Experimental

ICSE's experimental capabilities are being used to validate simulations of fires at multiple scales and to enhance understanding of fire spread, reaction kinetics, and soot formation. The validation results are also used to identify controlling mechanisms and to identify unexpected phenomena. ICSE has been studying controlled and uncontrolled burning of jet fuel under the C-SAFE program, agricultural materials under the SCERP program, and other materials, such as scrap tires.

Key personnel: Eric Eddings and JoAnn Lighty

Analytical

ICSE's analytical division applies nuclear magnetic resonance, chromatograph/mass spectrometry, particle characterization, and gas-phase instrumentation to improve the understanding of fires, particularly in the area of by-product formation.

Key personnel: Ron Pugmire and Henk Meuzelaar




Research Fires and explosions Aerosol formation Black liquor gasification Coal- and natural-gas-fired boilers Glass-melting furnaces Spreader stoker-fired combustors Diesel and gas-turbine engines Air toxics flares process heaters and cracking furnaces mixing tanks	Fires and Explosions Uncontrolled fires result in more than 3000 deaths and $10 billion in property damages per year. Emissions from these fires, as well as controlled fires for agriculture and forest management, contribute significantly to atmospheric organic particulate pollution, which in turn creates a health threat, impacts visibility, and contributes to global warming through the increased absorption of solar radiation. ICSE seeks to improve understanding of fires and explosions by combining tools for fire simulation, experiments, and analysis. Fire Simulations ICSE researchers perform fire simulations using a high fidelity fire model that spans the range of length and time scales from that characterize the fire physics in large diameter fires (> 1m). These scales range from chemical kinetics O(gigaseconds) at the molecular level to convective mixing O(1s) in the turbulent flow of the fire. Our fire model uses Large Eddy Simulation (LES) to resolve the large length and time scales that control the dynamics of the fire while the smaller, more universal scales are modeled. We couple LES with models for combustion chemistry, radiative heat transfer, and soot formation and destruction to solve problems ranging from design of large-scale fire experiments to developing protocols involving a bonfire test for transportation classification of hazardous materials. Within the C-SAFE program, ICSE researchers are working to predict the potential hazard of an explosive device immersed in a pool fire of transportation fuel by computing heat flux to the surface of the container. Key personnel: Philip Smith, Jennifer Spinti, and Jeremy Thornock Fire Model Our methodology for achieving predictability in fire simulations is to make decisions on algorithms and components based on a foundation of Verification and Validation (V&V). Verification quantifies the numerical accuracy of a code by comparison with known solutions. Validation assesses the modeling accuracy of a simulation by comparison with experimental data. The V&V hierarchy of a computational code is based on the intended use of the simulation and is composed of several levels of decreasing technical complexity: the full system or intended use of the model, subsystem cases, benchmark cases, coupled problems, unit level problems, and molecular processes. As one goes down the hierarchy, the amount of data available for comparison increases and the experimental uncertainties decrease. Each box in the hierarchy represents a data set or group of data sets that apply to the case identified by the label on the box. Experimental ICSE's experimental capabilities are being used to validate simulations of fires at multiple scales and to enhance understanding of fire spread, reaction kinetics, and soot formation. The validation results are also used to identify controlling mechanisms and to identify unexpected phenomena. ICSE has been studying controlled and uncontrolled burning of jet fuel under the C-SAFE program, agricultural materials under the SCERP program, and other materials, such as scrap tires. Key personnel: Eric Eddings and JoAnn Lighty Analytical ICSE's analytical division applies nuclear magnetic resonance, chromatograph/mass spectrometry, particle characterization, and gas-phase instrumentation to improve the understanding of fires, particularly in the area of by-product formation. Key personnel: Ron Pugmire and Henk Meuzelaar