摘要
为实现复杂声源局部声场精确重建，提出基于改进的HELS法的局部近场声全息（PNAH）技术。将实际声场视为声源各部分产生相干声场的叠加，利用小全息孔径测量声压求解正交基函数的线性组合系数，实现全息声压近场外推；用外推所得数据进行声场重建。仿真及实验结果表明，该方法能有效重建复杂声源声场，且重建精度较高。
Abstract
Fast Fourier transform (FFT)-based near-field acoustic holography (NAH) requires that the measurement aperture should completely enclose the source, which is impractical for large-scale sound sources. Helmholtz equation least squares (HELS) method allows for patch reconstruction. However, it’s not suitable for reconstructing acoustic radiation from coherent multiple sources or a complicated source which consists of several separated parts. To circumvent this difficulty and enhance the reconstruction accuracy, a new patch NAH technique based on the modified HELS method is proposed. The modified HELS method expresses the acoustic field of a complicated source as the superposition of the coherent acoustic radiation from all of its separated parts. Using the acoustic pressures reconstructed with the modified HELS method, the measurement surface is extended through an iterative procedure. In the end, taking the extrapolated pressures as input data, the acoustic field can be reconstructed more precisely. Numerical simulation and experimental results demonstrate that this method can reconstruct the acoustic field of a complicated source and enhance the reconstruction accuracy.
关键词
改进的HELS方法 /
数据外推 /
局部近场声全息 /
声场重
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Key words
modified HELS /
data extrapolation /
patch NAH /
acoustic field reconstruction
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王 冉;陈 进;董广明.
基于改进HELS方法的局部近场声全息技术研究[J]. 振动与冲击, 2014, 33(10): 157-161
WANG Ran;CHEN Jin;DONG Guang-ming.
Patch near-field acoustic holography based on the modified Helmholtz equation least squares method[J]. Journal of Vibration and Shock, 2014, 33(10): 157-161
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