Forward propagation of time evolving acoustic pressure: formulation and investigation of the impulse response in time-wavenumber domain.
Forward propagation of time evolving acoustic pressure: formulation and investigation of the impulse response in time-wavenumber domain.
复制标题
DOI：
10.1121/1.3216916
复制
发表时间：
2009-11
期刊：
影响因子：
--
通讯作者：
V. Grulier;S. Paillasseur;Jean-Hugh Thomas;J. Pascal;Jean-Christophe Le Roux
中科院分区：
文献类型：
--
作者：
V. Grulier;S. Paillasseur;Jean-Hugh Thomas;J. Pascal;Jean-Christophe Le Roux
本工作的目的是连续提供非平稳声源辐射的声压场。该方法从近场采集随时间波动的平面声场的声源出发，通过对每个时间步长的波数谱与脉冲响应进行卷积，然后进行逆傅立叶变换，得到相对于时间的瞬时声场。重建的质量取决于脉冲响应，脉冲响应由过渡频率和传播距离等参数组成。采样频率也影响用于计算的实际离散脉冲响应的误差。为了避免混叠，脉冲响应用切比雪夫或凯撒-贝塞尔滤波器进行低通滤波。实现脉冲响应的另一种方法包括将逆傅立叶变换应用于传播的理论传递函数。为了评估每种处理方法的性能，执行了涉及由非平稳信号驱动的多个源单极子的仿真测试。提出了一些指标来评估在前向平面中预测的时间信号的准确性。结果表明，使用数值实现的Kaiser-Bessel滤波器或逆傅里叶变换可以提供最准确的瞬时声信号。
The aim of this work is to continuously provide the acoustic pressure field radiated from nonstationary sources. From the acquisition in the nearfield of the sources of a planar acoustic field which fluctuates in time, the method gives instantaneous sound field with respect to time by convolving wavenumber spectra with impulse response and then inverse Fourier transforming into space for each time step. The quality of reconstruction depends on the impulse response which is composed of investigated parameters as transition frequency and propagation distance. Sampling frequency also affects errors of the practically discrete impulse response used for calculation. To avoid aliasing, the impulse response is low-pass filtered with Chebyshev or Kaiser-Bessel filter. Another approach to implement the impulse response consists of applying an inverse Fourier transform to the theoretical transfer function for propagation. To estimate the performance of each processing method, a simulation test involving several source monopoles driven by nonstationary signals is executed. Some indicators are proposed to assess the accuracy of the temporal signals predicted in a forward plane. The results show that the use of a Kaiser-Bessel filter numerically implemented or that of the inverse Fourier transform can provide the most accurate instantaneous acoustic signals.