湍流边界层激励下腔体内水动力自噪声预报与测量

Prediction and test of cavity's hydrodynamic selfnoise induced by turbulent boundary layer

循环水槽中试验测量了腔体内水动力自噪声,并与模态法建立的湍流脉动压力引起腔体自噪声预报进行比较验证。透声窗振动以简支边界为条件,腔体内部声波以刚性边界为条件模态展开,通过辐射边界条件建立模态耦合振动方程。在随机湍流脉动压力作用下,推导了模态振动方程在随机力激励下的自噪声功率谱响应。对循环水槽中5 m/s和8 m/s两种流速工况下的腔体水动力自噪声和湍流脉动压力进行了测试,结合测量的脉动压力预报方法可以计算腔体水动力自噪声量值,理论预报与试验测量结果大致吻合,趋势一致,为声呐罩材料选取及声学环境控制提供了一种分析方法。

The selfnoise in cavity is tested in the circling tank, prediction method of cavity＇s selfnoise induced by turbulent boundary layer is established. The dome vibration is using the simply supported boundary condition, the sound wave in the cavity is expanded using the rigid wall boundary condition, the modal coupling vibration equation between them is established using the radiation boundary condition. The turbulent boundary layer flunctuation pressure is random,the selfnoise power spectrum in the cavity is solved.Test of selfnoise and turbulent pressure is carried out in the circling tank when water flows at the speed of 5 m/s and 8 m/s, the result verifies the theoretical method can predict the real cavity＇s hydrodynamic noise approximately, the trends are similar, this provides one analytical method for sonar dome＇s material selection and noise control.