微重力下环境压力对火焰传播的影响

THE EFFECT OF AMBIENT PRESSURE ON THE FLAME SPREAD IN MICROGRAVITY

研究表明，在微重力环境中，当强制对流速度很小时，环境压力的增大会加强氧气的扩散，减弱辐射热损失对火焰的冷却效应，使火焰传播速度增大。但随着强制对流速度的增大，对流成为质量传递的主要途径，化学反应速率受化学反应动力学因素控制，火焰传播速度对压力的变化不敏感。

The study shows that, in microgravity when the forced convection is very weak, the oxygen diffusion can be enhanced, and the cooling effect of the radiative heat loss on the flame can be reduced by the increase of ambient pressure, as a result, the flam spreads faster. With the increase of the forced convection flow, convection becomes the main mode of mass transfer, and the chemical reaction is controlled by the chemical kinetics, the flame spread is not sensitive to the change of pressure.