二维多频声辐射问题的频域边界元分析方法

针对含有复杂频率成分声源的辐射问题,首先采用傅里叶变换将时域声源传播的控制波动方程转化为频域的Helmholtz方程;其次,选取多个等间隔的频率点作为采样频率,应用边界单元法求解各特征频率的Helmholtz方程,获得不同位置在各采样频率下的声压;最后,采用离散傅里叶反变换将频域声压幅值和相位转化为时域声压.边界元方法...

Frequency Domain Boundary Element Analysis Method for Two-Dimensional Broadband Acoustic Radiation

In view of the radiation problem of sound source with complex frequency components, firstly, by using Fourier transform, the governing wave equation of sound source propagation in time domain is transformed into Helmholtz equation in frequency domain. Secondly, with multiple equally spaced frequency points selected as the sampling frequency, the boundary element method is adopted to solve the Helmholtz equation of each characteristic frequency, thus obtaining the sound pressure at different positions under different sampling frequency. Finally, the amplitude and phase of sound pressure in frequency domain are transformed into time domain by an inverse discrete Fourier transform. In the application of the boundary element method, based on the conventional boundary integral equation of Helmholtz equation, the boundary is discretized by discontinuous Lagrange element, with the high order continuity of the test function at the node maintained as well. The calculation examples of acoustic eld analysis in two different structures are designed, thus verifying the correctness and accuracy of the algorithm.