脉冲爆震发动机流动形态与推力相关性研究

Investigation of Correlation Between Flow Structure and Thrust of Pulse Detonation Engine

采用数值分析方法研究了加装扩张、收敛、收扩型喷管PDE的流动情况,发现爆震波的传播、反射产生的波系是影响PDE推力的主要因素。本文对前人关于喷管构型与PDE推力关系互相矛盾的结论进行了分析,研究结果表明:加装扩张喷管的PDE,存在最优的面积比使冲量增益最大。加装收敛喷管的PDE,随面积比减小冲量增益逐渐减小。加装收扩喷管的PDE,当出口面积固定时,收敛角越大,冲量增益越小;当收敛角固定时,面积比越大,冲量增益会先增大后减小,但是收扩喷管总体冲量增益小于相应的扩张喷管。

In order to investigate the relationship between pulse detonation engine thrust and internal flow pattern,the flow of PDEs with divergent,convergent,convergent-divergent(CD)nozzles are analyzed by the method of numerical analysis method in this work.We found that the series of waves result from the transmission,reflection of detonation determine the thrust of PDE.In this paper,the contradictory conclusions drawn from previous studies on the relationship between nozzle configuration and thrust of PDE are analyzed.The simulation results indicated that the PDE of the divergent nozzle has the optimal area ratio to maximize the impulse gain.For PDE with convergent nozzle,the smaller area ratio means lower impulse gain.For PDE with CD nozzles,when the exit area is fixed,the larger the convergence angle and the smaller the impulse gain;when the convergence angle is fixed,the larger the area ratio is,the impulse gain will increase first and then decrease.Overall the impulse gain of convergent nozzle is smaller than the corresponding expansion nozzle.