2016-07-282016-07-282016-07-10ICES_2016_387http://hdl.handle.net/2346/67700United StatesSan Diego State University509ICES509: Fire Safety in Spacecraft and Enclosed HabitatsVienna, AustriaThe 46th International Conference on Environmental Systems was held in Vienna, Austria, USA on 10 July 2016 through 14 July 2016.S. Bhattacharjee, Department of Mechanical Engineering, San Diego State University, USAL.Carmignani, Department of Mechanical Engineering, San Diego State University, USAA. Simsek, Department of Mechanical Engineering, San Diego State University, USAOpposed flow flame spread over thin solid fuels can be divided into three different regimes based on the strength of the opposing flow velocity. In the thermal regime, the spread rate is independent of flow velocity. As the flow velocity is increased indefinitely, the kinetic regime is reached where the spread rate decreases with an increasing flow velocity, leading to blow off extinction. On the other hand, as the flow velocity is reduced indefinitely, which is possible only in a microgravity environment due to the lack of buoyancy induced flow, the radiative regime is reached where the spread rate decreases with a decrease in flow velocity, leading to radiative quenching of the flame. In this work, the role played by boundary layer in the radiative regime is studied both experimentally and computationally. The experiments were conducted with thin sheets of PMMA ignited in an opposed-flow configuration in a flow tunnel in the International Space Station. Fuel thickness, sample width, flow velocity, and the oxygen level were varied in these experiments. The results show that the flame size changes significantly as the flame spread across a developing boundary layer as predicted by the computational model. However, over the limited range of boundary layer development length, the experiment did not show a rise in spread rate with ta thinnin boudary layer as expected from the computational results.application/pdfengflame spreadmicrogravityfire safetyPMMAPresentation