Evaluation of the angular spectrum approach for simulations of near-field pressures
Evaluation of the angular spectrum approach for simulations of near-field pressures
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DOI：
10.1121/1.2812579
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发表时间：
2008-01-01
影响因子：
2.4
通讯作者：
J., Robert McGough
中科院分区：
文献类型：
--
作者：
Zeng, Xiaozheng;J., Robert McGough
基于二维快速傅里叶变换的角谱方法的实现针对方形超声换能器的近场压力模拟进行了评估，其中三维压力场是根据换能器表面上的法向速度分布计算的。压力场通过空间传播器或频谱传播器在空间频域中传播。空间传播器在计算网格的中心部分产生准确的结果，而由于应用于空间传播器的窗口的有限范围，在边缘附近产生显着的误差。同样，频谱传播器在空间频域中本质上是欠采样的，这会导致计算的压力场出现高频误差。通过角度限制可以缓解这种混叠问题。结果表明，在非衰减介质中，在截断感兴趣区域以排除加窗误差后，空间传播器比光谱传播器实现了更小的误差。对于衰减介质中的压力计算或以变迹活塞作为源的压力计算，空间和光谱传播器实现了相似的精度。在所有模拟中，使用空间传播器进行角谱计算比使用光谱传播器进行计算花费更多时间。 (c) 2008 年美国声学学会。
The implementation of the angular spectrum approach based on the two-dimensional fast Fourier transform is evaluated for near-field pressure simulations of square ultrasound transducers, where the three-dimensional pressure field is calculated from the normal velocity distribution on the transducer surface. The pressure field is propagated in the spatial frequency domain with the spatial propagator or the spectral propagator. The spatial propagator yields accurate results in the central portion of the computational grid while significant errors are produced near the edge due to the finite extent of the window applied to the spatial propagator. Likewise, the spectral propagator is inherently undersampled in the spatial frequency domain, and this causes high frequency errors in the computed pressure field. This aliasing problem is alleviated with angular restriction. The results show that, in nonattenuating media, the spatial propagator achieves smaller errors than the spectral propagator after the region of interest is truncated to exclude the windowing error. For pressure calculations in attenuating media or with apodized pistons as sources, the spatial and spectral propagator achieve similar accuracies. In all simulations, the angular spectrum calculations with the spatial propagator take more time than calculations with the spectral propagator. (c) 2008 Acoustical Society of America.