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原文传递 Determining the Cause of Reduced Concurrent Flame Spread over Thin Solid Fuels in Low Pressure and Low Gravity.

题名：	Determining the Cause of Reduced Concurrent Flame Spread over Thin Solid Fuels in Low Pressure and Low Gravity.
作者：	Thomsen, M; Carmignani, L; Fernandez-Pello, C; Fereres, S; Urban, D. L; Ruff, G. A.
关键词：	Fire safety##Microgravity
摘要：	The spread of flames over the surface of solid combustible materials is affected by theenvironmental conditions. Variables such as flow velocity, oxygen concentration, ambientpressure, partial gravity or microgravity, may change the material flammability and influencethe fire dynamics. This is an important fire safety issue for space exploration vehicles andspace habitats which will very likely have different environments than those currently usedon the International Space Station, such as reduced pressure and enriched oxygenconcentration (SEA). However, testing experimentally the materials to be used and qualifiedfor space exploration under these conditions is a difficult and expensive task. Here, numericalmodeling is used to understand the dominant physico-chemical processes on the concurrentflame spread over thin fabrics under reduced ambient pressure (and in turn, buoyancy) andvariable gravitational conditions. The numerical model uses the Fire Dynamics Simulator(FDS6) code with a single-step Arrhenius reaction rate for the solid phase decomposition.Different models are tested for the gas phase combustion kinetics. The model results arevalidated with experimental results obtained at similar reduced ambient pressure and flowconditions at 1 g. It is shown that as ambient pressure is reduced the flame spread rate over athin fabric is also reduced, both experimentally and numerically. Numerical results arecompared to an analytical approach previously developed to explain the experimental trends.Further interpretation of the model results provides information regarding the physics of theprocess and how they are affected by the lower pressure environments and gravity conditions.The results of this work provide guidance for potential on-earth testing for fire safety designin spacecraft and space habitats.
总页数：	13 pages