Measurement of structural intensity using boundary element method-based nearfield acoustical holography.
The regularization method for measurement of structural intensity (SI) using boundary element method (BEM)-based nearfield acoustical holography (NAH) is proposed. Spatial derivatives of normal displacement are necessary to obtain the structural intensity. The derivative operations amplify high-wavenumber component of measurement noise and contaminate the measurement result of SI. To overcome this difficulty, regularization method for measurement of SI using fast Fourier transform-based NAH has been introduced. In this paper, this regularization method is modified for the BEM-based NAH. The BEM-based NAH avoids the aperture replication problem; therefore, measurement aperture for BEM-based NAH can be set smaller than that for FFT-based NAH. The effectiveness of the proposed method is demonstrated by experiments.
Saijyou
Kenji
K
Technical R & D Institute, Ministry of Defense, 3-13-1 Nagase, Yokosuka, 239-0826, Japan. saijyou-kenji@com.home.ne.jp
D000162:Acoustics; D003198:Computer Simulation; D006696:Holography / Q000379:methods*; D007091:Image Processing, Computer-Assisted; D008961:Models, Structural; D014867:Water
D014867:Water