Effect of sensor proximity over the non-conformal hologram plane in the near-field acoustical holography based on the inverse boundary element method

The inverse boundary element method (BEM) is a numerical procedure whereby sound pressure measurements in the near field are used to predict the vibration on the vibrating surface. After the vibration (or particle velocity for an opening) is determined, the sound pressure in the far field can be predicted using a forward BEM analysis. This paper will examine a particular example where the far field sound pressure was predicted for a generator set. The results indicate that the vibration predicted by the inverse BEM can be used to accurately predict the sound pressure as far away as 7 meters from the source.

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A Burton–Miller inverse boundary element method for near-field acoustic holography

The Journal of the Acoustical Society of America ◽

10.1121/1.3133923 ◽

2009 ◽

Vol 126 (1) ◽

pp. 149-157 ◽

Cited By ~ 9

Author(s):

D. J. Chappell ◽

P. J. Harris

Keyword(s):

Boundary Element Method ◽

Boundary Element ◽

Near Field ◽

Acoustic Holography ◽

Inverse Boundary ◽

Element Method

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Comparisons of regularization methods and regularization parameter selection methods in sound source identification using inverse boundary element method

Noise Control Engineering Journal ◽

10.3397/1/376720 ◽

2019 ◽

Vol 67 (3) ◽

pp. 219-227

Author(s):

Youhong Xiao ◽

Qingqing Song ◽

Shaowei Li ◽

Guoxue Lv ◽

Zhenlin Ji

Keyword(s):

Boundary Element Method ◽

Boundary Element ◽

Transfer Matrix ◽

Sound Source ◽

Source Identification ◽

Regularization Parameter ◽

Vibration Velocity ◽

Regularization Methods ◽

Inverse Boundary ◽

Element Method

In noise source identification based on the inverse boundary element method (IBEM), the boundary vibration velocity is predicted based on the field pressure through a transfer matrix of the vibration velocity and field pressure established on the Helmholtz integral equation. Because the matrix is often ill-posed, it needs to be regularized before reconstructing the vibration velocity. Two regularization methods and two methods of selecting the regularization parameter are investigated through the simulation analysis of a pulsating sphere. The result of transfer matrix regularization is further verified through the reconstruction of the vibration of an aluminum plate. Additionally, to reduce the large errors at some frequencies in the reconstruction result, increasing the number of measuring points is more effective than reducing the distance between the measurement plane and the sound source.

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USE OF RIGID REFLECTORS FOR THE VIRTUAL INCREASE OF FIELD DATA IN THE NEAR-FIELD ACOUSTICAL HOLOGRAPHY

Journal of Computational Acoustics ◽

10.1142/s0218396x07003202 ◽

2007 ◽

Vol 15 (01) ◽

pp. 49-61 ◽

Cited By ~ 1

Author(s):

SUNG-IL KIM ◽

JEONG-GUON IH ◽

JI-HOON JEONG

Keyword(s):

Boundary Element Method ◽

Transfer Matrix ◽

Field Data ◽

Near Field ◽

Measurement Data ◽

Source Reconstruction ◽

Matrix Equations ◽

Inverse Boundary ◽

Additional Information ◽

Acoustical Holography

This paper suggests the use of rigid reflectors to provide additional information for source reconstruction in near-field acoustical holography based on the inverse boundary element method. The additional field pressure and transfer matrix equations introduced provide a virtual increase in the measurement data without increasing the number of sensors or altering their arrangement, which could cost more than using reflectors. In order to validate this method, we successfully reconstruct a vibrating ellipse.

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