微小重力環境における低速空気流中のETFE被覆導線の燃焼挙動(熱工学,内燃機関,動力など)

概要

論文の詳細を見る
Opposed flame spreading over ETFE (ethylene-tetrafluoroethylene co-polymer) insulated wire, which is used for actual wire in space, in low air flow velocity has been investigated under microgravity environment. The experiments were performed with Japan Microgravity Center (JAMIC) 10 s dropshaft and NASA's KC 135 parabolic flight. Experiments were performed with changing O_2 concentration, 35 and 40%, external air flow velocity, 0 (quiescent) -22cm/s and dilution gas, N_2, CO_2, He. The sample of 0.32mm inner core diameter with 0.15mm insulation thickness was used. The results showed that flame spread rate over wire insulation was strongly affected by air flow velocity and the dilution gases. Flame spread with N_2 dilution had maximum value in a low flow velocity region. However, CO_2 dilution resulted in monotonic increase in flame spread rate with decrease in air flow velocity and the maximum flame spread at V_e=0cm/s (quiescent). The different dependency of the spread rate on flow velocity with different dilution gas was explained by the reabsorption effect of CO_2 gas ahead of flame front. Reabsorption of radiation heat with CO_2 gas recovers the radiation heat from the flame and prevent the flame temperature decrease even in very low flow velocity region, which is known as radiation control region for optically thin gas.
社団法人日本機械学会の論文
2004-04-25