不同高度通道内热薄燃料火焰传播特性的研究

为探究通道高度对逆风火焰传播特性的影响，采用实验、数值模拟、理论分析方法对微重力条件下不同高度通道内热薄燃料火焰传播特性进行了研究。通道高度分别为10mm, 14mm和60mm的短时落塔微重力实验结果表明，相同逆风气流速度时，随通道高度增加，火焰传播速度逐渐增大，且10mm, 14mm和16mm高度通道下的火焰长度比约为通道半高度比的二次方关系。数值模拟与理论分析表明，微重力条件下，随通道高度增加，火焰传播速度、火焰长度先增大再减小，呈非单调的变化趋势。燃烧热释放速率随高度变化呈非单调变化趋势，同火焰传播速度变化规律基本一致。

Research on Flame Spread over Thin Solid Fuels in Different Channel Heights

In order to determine the effect of the channel height to flame properties, drop tower experiments, numerical simulation and theoretical analysis methods are used to study flame propagation properties over thin solid fuels in different height channels under the microgravity condition. The height of the drop tower microgravity experiments is 10, 14 and 60mm. The short time microgravity experiment results in 10, 14 and 60mm channel heights indicate that flame spread rates increase with the increase of channel heights under same flow velocities. The flame lengths ratio of 10 and 14mm channel heights is proportional to square of half channel height ratio. The results of numerical simulation and theoretical analysis show that flame spread rates and flame lengths are nonlinearly change with the increase of channel heights increase firstly, and then decreased. The heat release rate increased firstly and then decreased with the increase of channel heights, thus inducing to the nonlinear trend occurred in flame spread rate.