障碍物对脉冲爆震火箭发动机性能影响的实验研究

Experimental Study on Effects of Obstacles on Performance of Pulse Detonation Rocket Engines

关键词:  脉冲爆震火箭发动机  无阀自适应  障碍物  DDT距离  推进性能

Key words:  Pulse detonation rocket engines  Valveless self-adaptive  Obstacle shapes  DDT distance  Propulsive performance

摘要:

为了探究障碍物对脉冲爆震火箭发动机在无阀自适应工作方式下性能的影响，采用汽油为燃料，富氧空气为氧化剂，开展了工作频率为20Hz的无阀式多循环实验研究。实验中使用Shchelkin螺旋、螺旋凹槽、环形凹槽和孔板作为障碍物，并分析了其对起爆和推进性能的影响。研究结果表明，Shchelkin螺旋、螺旋凹槽和环形凹槽在阻塞比BR=0.36，0.46和0.56时都可实现PDRE的稳定工作，孔板在BR=0.56时无法实现爆震的起始；Shchelkin螺旋的DDT距离和DDT时间最短；实验测得的平均推力较理想流动模型理论值有13.3%~39.3%的亏损，BR=0.36的Shchelkin螺旋推力损失最小；螺旋凹槽与环形凹槽的DDT距离和DDT时间较长，没有明显的推力增益。

Abstract:

In order to explore the effects of obstacle shapes on the performance of pulse detonation rocket engines under valveless self-adaptive working mode， the multi-cycle experiment was carried out with the operating frequency of 20Hz. Gasoline was utilized as fuel，and oxygen-enriched air as oxidizer. Shchelkin spirals， spiraling grooves， annular grooves and orifice plates were selected as obstacles in the experiment， and their effects on initiation and propulsion performance were analyzed. The results indicate that， fully developed detonation waves are successfully obtained in the PDRE when Shchelkin spirals， spiraling grooves and annular grooves with blockage ratio of 0.36， 0.46 and 0.56 are used as obstacles， while there is no transition to detonation occurred when the blockage ratio of orifice plates is 0.56. The DDT distance and DDT time of Shchelkin spirals are the shortest. The average thrust measured in the experiments is 13.3%~39.3% lower than the theoretical value of the ideal model， and the thrust loss of Shchelkin spirals with blockage ratio of 0.36 is the smallest. The DDT distance and DDT time of spiraling grooves and annular grooves are longer， and there is no obvious effect of enhancing thrust.