摘要
近场外推是小全息孔径近场声全息(Patch NAH)的关键步骤,为进一步提高外推精度和计算效率,提出一种新的基于快速Fourier变换算法的源强模拟技术,并将其应用于Patch近场声全息的近场外推问题.首先将虚拟源连续分布在一矩形面上,并将虚拟源强密度函数进行双向Fourier级数展开,得到具有快速Fourier变换(FFT)形式的声压表达式,这样可以利用二维FFT算法加速计算,然后根据小全息面上声压数据求出源强展开系数,从而利用声压表达式实现近场外推.由于采用连续分布的虚拟源和二维FFT加速技术,本文的外推方法具有实施简单,外推精度高,计算速度快的特点.数值算例验证了该方法的正确性和有效性.
Near-field extrapolation is a key of patch near-field acoustic holography （Patch NAH）. In order to further improve the extrapolation accuracy and computational efficiency, a new source simulation extrapolation technique based on the FFT algorithm is proposed to solve hologram data extrapolation problem. First, virtual sources are continuously distributed on a rectangular surface and the source density distributed function is expanded into 2D Fourier series. So the sound pressure can be expressed by the form of 2D discrete fast Fourier transform and use the 2D-FFT to speed up the calculation. By using the small measured aperture pressure data, the expansion coefficients earl be obtained to perform near-field sound pressure extrapolation of the larger holographic surface. Owing to the continuous distribution of the virtual sources and the 2D-FFT acceleration technique, this new extrapolation method is simple for applications, and shows high accuracy and efficiency. The effectiveness of the proposed method is verified by the numerical example.
出处
《广西工学院学报》
CAS
2013年第1期29-32,共4页
Journal of Guangxi University of Technology
基金
广西自然科学基金(2012GXNSFAA053207
2013GXNSFAA019318)资助
关键词
源强模拟技术
声全息
近场外推
快速FOURIER变换
source simulation technique
acoustic holography
near-field extrapolation
fast Fourier transform
