高超声速流场等离子体合成射流逆向喷流特性

Reverse jet characteristics of plasma synthetic jet in hypersonic flow field

为了研究在高超声速条件下逆向等离子体合成射流流场特性,进行了试验和数值研究。在马赫数为8的高超声速来流中,通过比较试验和仿真中纹影以及激励器出口压力监测结果,分析了反向等离子体合成射流的流场变化。验证了高超声速条件下,反向等离子体合成射流激励器出口压力振荡,是腔体内多次回填产生多次喷流导致多道激波扫过激励器出口所导致的;等离子体合成射流增大了射流区域外的气体质量流量,同时向上游传播的前驱激波与弓形激波融合为一道激波;在高动量射流的作用下产生的涡环、逆流产生的低压区以及高温低密度等离子体射流降低了当地马赫数,使得激波穿透深度增加。

To study the flow field characteristics of the reverse plasma synthetic jet under hypersonic conditions,experimental and numerical studies were carried out.In the hypersonic incoming flow with Mach number 8,the flow field variation of the reverse plasma synthetic jet was analyzed by comparing the schlieren and exciter outlet pressure monitoring results in the experiment and simulation.It is verified that under hypersonic conditions,the outlet pressure oscillation of the reverse plasma synthesis jet actuator is caused by multiple jets generated by multiple backfilling in the cavity,causing multiple shocks to sweep over the actuator outlet.The plasma synthesis jet increases the mass flow of the gas outside the jet area,while the precursor shock propagating upstream merges with the bow shock wave into a single shock.The vortex rings produced under the action of high-momentum jets,the low-pressure regions created by counter-currents,and the high-temperature low-density plasma jets reduce the local Mach number,resulting in an increase in the shock penetration depth.