Determination of the directivity of a planar noise source by means of near field acoustical holography, 1: theoretical background

1995 ◽  
Vol 180 (1) ◽  
pp. 99-118 ◽  
Author(s):  
M.A. Rowell ◽  
D.J. Oldham
Keyword(s):  
Noise Source ◽  
Near Field ◽  
Theoretical Background ◽  
Acoustical Holography

scholarly journals An Improved Algorithm for Noise Source Localization Based on Equivalent Source Method

2016 ◽  
Vol 2016 ◽  
pp. 1-13
Author(s):  
Zhongming Xu ◽  
Qinghua Wang ◽  
Yansong He ◽  
Zhifei Zhang ◽  
Shu Li ◽  
...  
Keyword(s):  
Source Localization ◽  
High Frequency ◽  
Noise Source ◽  
Near Field ◽  
Low Frequency ◽  
Equivalent Source ◽  
Source Method ◽  
Functional Equivalent ◽  
Acoustical Holography ◽  
Equivalent Source Method

Near-field acoustical holography (NAH) based on the equivalent source method (ESM) is an efficient method applied for noise source identification. Asl2-norm-based regularization cannot produce a satisfactory solution of the ill-conditioned problem in high frequency, the conventional ESM is restricted to relatively low frequency, and the resolution of conventional ESM in middle to high frequency remains a limitation open to investigation. This article presents an algorithm known as improved functional equivalent source method (IFESM), designed to enhance the resolution of conventional ESM. This method is developed in the framework of wideband acoustical holography (WBH) combining with functional beamforming (FB). Through numerical simulations, it is proved that the proposed method can localize noise with higher resolution compared with WBH and conventional ESM, and the ghosts on noise source map can be suppressed effectively. The validity and the feasibility of the proposed method are manifested by experiments including single-source and coherent-source localization.

Military jet noise source imaging using multisource statistically optimized near-field acoustical holography

2016 ◽  
Vol 139 (4) ◽  
pp. 1938-1950 ◽  
Author(s):  
Alan T. Wall ◽  
Kent L. Gee ◽  
Tracianne B. Neilsen ◽  
Richard L. McKinley ◽  
Michael M. James
Keyword(s):  
Noise Source ◽  
Near Field ◽  
Jet Noise ◽  
Source Imaging ◽  
Acoustical Holography

Near-field acoustical holography-based noise source analysis of an installed, afterburning F404 engine

2021 ◽  
Vol 150 (4) ◽  
pp. A213-A213
Author(s):  
Logan T. Mathews ◽  
Kevin M. Leete ◽  
Kent L. Gee ◽  
Alan T. Wall
Keyword(s):  
Noise Source ◽  
Near Field ◽  
Source Analysis ◽  
Acoustical Holography

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

2007 ◽  
Vol 15 (01) ◽  
pp. 49-61 ◽  
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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