地面模拟静止微重力环境中导线先期着火特性研究

针对在微重力环境中运行的载人航天飞行器上的电缆和导线在工作时由于电流过载导致温度升高而引起着火的情况,提出了“功能模拟”实验原理,并且利用地面实验设备对微重力环境下导线的着火前期特性进行了功能模拟实验研究．通过实验,得到了在微重力情况下由于浮升力的减小使自然对流减弱导致电流过载时导线的热平衡温度高于地面正常重力情况,从而证明了这正是引起航天飞行器着火的潜在点火源．

Functional Simulations of the Fire Precursor of the Wire Insulation in Quiescent Microgravity Enviroment

The experimental principle of Functional Simulation (FS) was proposed aiming at the fire in the space shuttle caused by the electrical wire overload or short circuit because it is of great important significance of study on the wire insulation flammability in microgravity for fire safety. The concept and conditions of the FS were presented in this paper. Experimental setup was established according to the FS concept. The study on the fire precursor of the wire in microgravity was accomplished by the proposed experiment facility at normal gravity. The experimental results show that the equilibrium temperatures of wire insulation were much higher in the microgravity than that in the normal gravity condition with the overload currents because the convection is greatly reduced and suppressed. Meanwhile, the wire was molten down and the insulation was burnt observed in the experiments. These results furtherly confirmed that the wire is the potential ignition source in the case of overloading or short circuit in the space shuttles.