AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
Characterization of Smoke for Spacecraft Fire Safety
XIAOLIANG WANG, Hao Zhou, W. Patrick Arnott, Marit Meyer, Samuel Taylor, Hatef Firouzkouhi, Hans Moosmuller, Judith Chow, John Watson, Desert Research Institute
Abstract Number: 311 Working Group: Combustion
Abstract Fire is among the most catastrophic threats to space activities. Conventional spacecraft smoke detectors are not optimized for detecting space smoke, which differs from that on Earth due to differences in fuel materials, burning conditions, and particle formation/transformation processes as well as lack of gravity. This study characterizes smoke from combustion of spacecraft-relevant materials with an aim to improve space fire detection. Three spacecraft-relevant materials, cotton lamp wick, Poly(methyl methacrylate) (PMMA), and Nomex® fabric were burned in smoldering and flaming conditions. A suite of instruments was used to characterize gas and particle emissions, including carbon monoxide, carbon dioxide, volatile organic compounds, particulate matter mass, particle size distribution, light scattering and absorption, and particle chemical composition. Particles emitted from flaming PMMA were fractal-like soot agglomerates, different from the near spherical particles found for other fuels and burning conditions. Particles from smoldering cotton combustion had a bimodal number size distribution, while those from other fuels and test conditions exhibited mono-modal lognormal number size distributions. Smoke particles from flaming PMMA combustion were black with single scattering albedos <0.3, while particles from other burned materials demonstrated low light absorption, with single scattering albedos >0.9 at 405-781 nm. Mass extinction coefficients were 6.4 m2/g for flaming PMMA and 2.2-3.5 m2/g for smoldering combustions at 632.8 nm. Carbon monoxide and particulate matter mass emission factors were higher for smoldering than for flaming combustions, while carbon dioxide emission factors were higher for flaming combustions. These data are of essence for optimizing spacecraft smoke detector designs. They are also useful for numerical modeling of smoke emission and transport.