爆震室长度对反传影响的数值研究

 对吸气式脉冲爆震发动机(APDE)的反传进行了数值研究,分析了反传的形成及传播特性,得到了爆震室长度对反传的影响。结果表明:反压能够影响整个进气道,缩短爆震室长度有利于降低反压强度。要使反压强度大幅下降,爆震室长度需要大幅缩短。爆震室长度较长时,增长爆震室长度对反压强度影响不大,但会延长进气道的泄压时间。反压会造成进气道内流动反向,反流速度随着爆震室长度增长而增大,爆震室较短时这个趋势更加明显。反传燃气的影响区域明显小于反传压力,当爆震室长度缩短到一定程度时,燃气不会传入进气道。爆震室长度较长时,爆震室上游与进气道下游之间的流道内会出现燃气分布不连续的现象。

Numerical Investigation of Effect of Detonation Chamber Length on Back-propagation

The phenomenon of back-propagation of an air-breathing pulse detonation engine (APDE) is numerically investigated. The formation and propagation characteristics of the back-propagation phenomenon are analyzed. The effect of the detonation chamber length on back-propagation is analyzed. The results show that the back pressure can influence the whole inlet. Shortening the length of the detonation chamber has the benefit of reducing the back pressure intensity; a substantial decline of back pressure intensity depends on a significant reduction of the detonation chamber length. However, increasing the detonation chamber length has little effect on back pressure intensity when the chamber is relatively long, but it prolongs the pressure release time. The back pressure will cause the flow to reverse in the inlet. The velocity of the reversed flow increases with increasing chamber length, which is more obvious when the chamber length is relatively short. The hot gas covers a much smaller region than the back pressure. The hot gas will not travel into the inlet when the chamber length is short enough. The distribution of the hot gas will be discontinuous in the region between the upstream chamber and downstream inlet.