微重力下固体材料燃烧特性的地面实验模拟方法研究

摘要

The flame spread characteristics over thermally thin solid materials and the flammability limits of such materials have been investigated in horizontal narrow channels by experimental measurements and numerical simulations. The mechanism of narrow channel device to produce a microgravity environment is discussed. For the low forced flow velocities typically expected in space facilities, flame spread characteristics in microgravity can be effectively reproduced in narrow channels with height of 10~14 mm. Moreover, the measured flammability data in the narrow channels are close to those obtained in microgravity environment. The maximum buoyant velocity is estimated to be about 5 cm/s in the narrow channels. Compared with typical normal gravity test channel with relatively large height, buoyant effect is essentially suppressed. Consequently, a simulated microgravity environment can be produced with the horizontal narrow channels.%在对水平窄通道内典型热薄固体材料的燃烧特性进行实验和数值模拟的基础上,分析了材料表面火焰传播、材料可燃极限与微重力实验结果的相似性,以及窄通道实验模拟微重力材料燃烧特性的机理。研究表明,在航天器舱内常见的低速气流条件下,高度为10mm～14mm的窄通道能较好地模拟微重力环境中材料表面火焰传播的特征,并复现材料的可燃极限曲线;窄通道内火焰诱导的浮力流动速度的最大值约为5cm/s,与常规实验通道（高度较大）相比,窄通道能够有效地限制自然对流,进而提供模拟微重力条件下材料燃烧特性的实验环境。