基于声压修正边界元方法的气动噪声数值模拟

Numerical Simulation of Aerodynamic Noise Based on Acoustic Pressure Correction Boundary Element Method

为考虑非紧致固体边界散射作用的影响,通过声模拟与边界元相结合的声压修正方法预测流体流动引起的噪声,将所分析的问题降低一维,能够满足无限远处边界条件。频率不是很高时,四极子源辐射的声强度远小于边界散射声强度,可以忽略耗时的四极子源项体积积分计算。通过傅立叶变换在频域求解声压方程,避免了繁琐的时间延迟计算。

Considering the scattering effect of non-compact boundary, an acoustic pressure correction method is presented to predict the aerodynamic noise using a combination of acoustic analogy and boundary element method. The boundary element method can reduces the problem by one dimension, which will greatly reduce the computation quantity, and also automatically satisfies the infinite far boundary conditions. When the acoustic frequency is not very high, the intensity of sound radiated from the quadrupole source is usually much less than that of the scattering sound, and the time consuming quadrupole integral could be avoided. Implementing Fourier transform to solve the acoustic pressure correction equation in the frequency domain can avoid cockamamie retarded time calculation.