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LI Weibing
CHEN Jian
YU Fei
CHEN Xinzhao
Institute of Sound and Vibration
Research,
Hefei University of Technology,
Hefei 230009, China
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NEAR-FIELD ACOUSTIC HOLOGRAPHY FOR
SEMI-FREE ACOUSTIC FIELD BASED ON WAVE SUPERPOSITION APPROACH*
Abstract:
In the semi-free acoustic field, the actual acoustic pressure at any point is composed of two parts: The direct acoustic pressure and the reflected acoustic pressure. The general acoustic holographic theories and algorithms request that there is only the direct acoustic pressure contained in the pressure at any point on the hologram surface, consequently, they cannot be used to reconstruct acoustic source and predict acoustic field directly. To take the reflected pressure into consideration, near-field acoustic holography for semi-free acoustic field based on wave superposition approach is proposed to realize the holographic reconstruction and prediction of the semi-free acoustic field, and the wave superposition approach is adopted as a holographic transform algorithm. The proposed theory and algorithm are realized and verified with a numerical example, and the drawbacks of the general theories and algorithms in the holographic reconstruction and prediction of the semi-free acoustic field are also demonstrated by this numerical example.
Key words:
Near-field acoustical holography Semi-free acoustic field Wave superposition approach
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