后壁倒角对空腔噪声的抑制效果

对不同后壁角度（δr）时长深比为9的空腔模型底面中心线上的声压级分布、不同测点声压频谱特性进行分析,着重研究了后壁倒角对空腔噪声的抑制效果。结果表明,无论是在亚声速还是在超声速,空腔后壁角度增大,使得空腔内不同测点的声压级都有所降低,特别是后壁处的声压级明显降低;对不同测点的声压频谱特性也有一定影响,特别是对空腔流激振荡峰值频率时的噪声声压级有较为明显的抑制效果。可见,增大空腔后壁角度对空腔噪声有一定的抑制效果。

Suppression effect of rear-face angle of cavity on aerodynamic noise

Sound pressure level（SPL） distributions on the cavity floor centerline and sound pressure frequency spectrum（SPFS） characteristics on the different measurement positions are analyzed,and suppression effect of rear-face angle（δr） of the cavity on aerodynamic noise inside the cavity is investigated.The cavity studied was with the length-to-depth ratio of 9 and different rear-face angles.The results indicate that increase in rear-face angle of the cavity induces an occurrence that SPL on the different measurement positions decreases,especially obvious for the region upstream of the cavity rear-face.Furthermore,the increasing the rear-face of the cavity has an obvious suppression effect on the SPL at the flow oscillation frequencies.Therefore,increase in the rear-face angle of the cavity can result in some advantageous effect on the aerodynamic noise inside the cavity.