凹面腔内的激波会聚冷态实验

为研究两级脉冲爆震发动机中激波聚焦起爆技术,研制了激波会聚起爆原理样机,建立了整套实验系统.利用三维激波会聚起爆原理样机,开展了导流角度、气流出口面积、尾喷管扩张角、凹面腔与射流入口间距离等对凹面腔内气动振荡频率和压力影响的冷态实验研究.结果表明:导流角增大,气动振荡频率增大;气流出口面积减小,气动振荡频率增大,凹面腔底部动态压力脉动幅值增大;喷管扩张角度增大,气动振荡频率数目增多;随着凹面腔与环形射流入口间的距离L增长,气动振荡频率降低,凹面腔底部动态压力脉动幅值降低. 

Experiment on shock wave focus in resonator

In order to investigate three-dimensional shock wave focus of two-stage pulse detmation engine(PDE), three-dimensional shock wave focus initiation principle device was independently designed, and a complete set of experimental system was established.Experiments on non-reaction three-dimensional shock wave focus were conducted.It is found that resonant frequency increases with the increase of the incidence angle of resonator.As airflow exit area decreases, resonant frequency of resonator increases and the dynamic pressure amplitude of resonator bottom increases.As nozzle diverging angle increases, the highest alpha-frequency increases and the quantity of beta-frequency increases.When the nozzle diverging angle is 30°, the dynamic pressure amplitude of resonator bottom is maximal.As ‘L’ increases, resonant frequency decreases and the dynamic pressure amplitude of resonator bottom decreases.