Effect of Acoustic Environment on the Burning Rate of Solid Propellants
Effect of Acoustic Environment on the Burning Rate of Solid Propellants
复制标题
声环境对固体推进剂燃烧速率的影响
作者：
J. E. Crump;E. Price
在固体推进剂的不稳定燃烧过程中，燃烧表面会受到邻近气体环境的剧烈振荡，导致推进剂燃烧速率发生较大变化。通过使用专门设计的燃烧器，发现可以通过中断燃烧来确定对推进剂燃烧速率的影响。由于振荡行为的驻波性质，可以将推进剂表面上每个点的燃烧速率的变化与声环境的性质相关联。据观察，燃烧速率因声压而降低，因声速（双基推进剂）而增加，这两种效应具有相当的强度。发现不稳定的火箭发动机和通风容器点火过程中平衡压力的波动很容易用间断燃烧试验中获得的燃烧速率效应来解释，前提是点火过程中的声学行为足够简单，易于分析。然而，在某些条件下观察到一类单一的行为；当不稳定切向模式（第一模式）的频率是不稳定轴向模式频率的整数倍时，燃烧过程中的特征时间发生燃烧速率的急剧增加。
During unstable combustion of solid propellants, the burning surface is exposed to severe oscillations in the adjoining gas environment, and large changes in burning rate of the propellant result. By using specially designed burners, it was found possible to determine, by interrupting burning, the effect on the propellant burning rate. Because of the standingwave nature of the oscillatory behavior, it was possible to correlate the change in burning rate at each point on the propellant surface with the nature of the acoustic environment. It was observed that burning rate is decreased by acoustic pressure and increased by acoustic velocity (double-base propellants), the two effects being of comparable magnitude. The fluctuations in equilibrium pressure during unstable rocket motor and vented vessel firings were found to be readily explainable in terms of the burning-rate effects obtained from the interrupted burning tests, provided the acoustic behavior during the firings was simple enough to analyze. However, a singular class of behavior was observed under certain conditions; dramatic increases in burning rate occurred at characteristi c times during burning when the frequency of the unstable tangential mode (first mode) was an integral multiple of the frequency of an unstable axial mode.