超音速射流噪声突变现象的实验和数值模拟研究

摘要

The measurement results of the supersonic jet noise indicate that the noise generated by some nozzles doesn't decrease as the reservoir pressure decreases,but increases rapidly in particular pressure condition.Experimental exploration and numerical simulation of two kinds of nozzles are conducted in order to predict whether the jet noise will change suddenly in the nozzle design period.The results show that the jet noise is strongly related with the centerline total pressure in the flow field,so the change of the total pressure can be used to judge whether the jet noise increases suddenly or not.Therefore,the sudden change phenomenon of the jet noise can be predicted by means of simulation research in nozzles' design.%在利用“放气法”测量喷管的超音速射流噪声的实验过程中,发现部分结构喷管产生的射流噪声大小不是随着上游压强的减小而减小,而是在特定压强点出现突增现象.为了在喷管的设计阶段就能预测其喷流噪声是否发生突变,对两种结构喷管的射流流场进行了实验和数值模拟研究.结果表明,射流流场的轴线总压和噪声声压级存在强相关性,可将流场总压的变化作为噪声是否突变的判据.因此,在设计喷管时对其射流流场进行仿真研究,就可预测其噪声突变现象的产生.