振动噪声和气动噪声统一分析方法的理论研究

首先对振动声学和气动声学理论进行了关联性分析,证明了振动声辐射的积分方程是FW-H方程的一种特殊形式,表明声比拟理论不仅适用于气动噪声的预测,而且同样适用于振动噪声的预测,是分析噪声产生机理的普适化理论。然后利用FW-H方程计算了球脉动和振动辐射噪声的声压级,计算结果和采用振动声学理论分析得到的结果完全一致。在此基础上,对流固耦合噪声的预测方法进行了探讨分析。结果表明,流体和弹性薄壳体耦合作用激发的噪声仅取决于流体的运动速度和流固界面的作用力,而与壳体边界的振动速度无直接相关。

Theoretical Analysis on the unified method for vibroacoustics and aeroacoustics

Relationship between the vibroacoustic and aeroacoustic theory has been analyzed. Result shows the boundary integral equation of vibrational noise is a specific form of the FW-H equation, which implies acoustic analogy is not only suitable for predicting the aerodynamic noise but also for the vibrational noise, and it is a general theory for noise prediction. After that, sound pressure at far field radiated from pulsating and vibrational sphere is computed using acoustic analogy, and the result is agreement with that from the vibroacoustic theory. Lastly, prediction method of noise radiated from the fluid-structure interaction is discussed, and result indicates that the noise radiated from the thin shells just depends on the fluid velocity and force on the solid surface but not on the vibrational velocity of the shells.