基于改进HELS方法的局部近场声全息技术研究  

Patch near-field acoustic holography based on modified Helmholtz equation least square method

作　　者：王冉[1] 陈进[1] 董广明[1] 

机构地区：[1]上海交通大学机械系统与振动国家重点实验室,上海200240

出　　处：《振动与冲击》2014年第10期157-161,共5页Journal of Vibration and Shock

基　　金：国家自然科学基金重点项目(51035007);国家自然科学基金面上项目(51175329)

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。Fast Fourier transformation （FFT ）-based near-field acoustic holography （NAH ） requires that measurement aperture should completely enclose a source,but it is impractical for large-scale sound sources.Helmholtz equation least square （HELS ） method allows patch acoustic field reconstruction. However, it＆#39;s not suitable for reconstructing acoustic radiations from coherent multiple sources or a complicated source consisting of several separated parts.To overcome this difficulty and enhance reconstruction accuracy,a new patch NAH technique based on the modified HELS method was proposed.The acoustic field of a complicated source was expressed as the superposition of coherent acoustic radiations from all of its separated parts with the modified HELS method.Using the acoustic pressures reconstructed with the modified HELS method,the measurement surface was extended through an iterative procedure. Finally,taking the extrapolated pressures as input data,the acoustic field was reconstructed more precisely.Numerical simulation and experimental results demonstrated that this method can be used to reconstruct the acoustic field of a complicated source and raise 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 

分 类 号：TB532[理学—物理]