微重力环境中的蜡烛火焰

THE CANDLE FLAMES IN MICROGRAVITY

对蜡烛火焰动态特征的分析表明，从正常重力状态过渡到微重力状态，火焰的空气动力学特征比质量和能量的传输特征的变化快。通过一台差分干涉仪首次测量得到了微重力环境中蜡烛火焰的温度。结果表明，微重力蜡烛火焰的温度小于正常重力蜡烛火焰的温度。微重力蜡烛火焰之所以呈蓝色是因为其温度小于烟黑生成的阈值温度1300K。但当环境氧浓度足够高时，火焰温度大于烟黑生成的阈值温度，火焰中明显有烟黑生成，颜色为亮黄色。

The analysis of transient process of candle flame from normal gravity to mi-crogravity shows that the variation of the aerodynamic feature is much faster than that oftransport feattire. The candle flame temperattire was measured by the use of an illterfer-ometer in microgravity. The results show that candle flame temperature in microgravity is indeed lower than that in normal gravity. The candle flame temperature in microgravity at 21%O2/79%N2 concentration is lower than the threshold temperature of soot formation of 1300K. That is the reason why the candle flame is dim blue at microgravity. However, if the ambient oxygen concentration is high enough, the candle flame temperature will be higher than the tlireshold temperature, so that soot will produce, and the color of candle flame will be bright yellow all the time even in microgravity.