ZHOU Linkai FAN Jun TANG Weilin 

(School of Naval Architecture, Ocean and Civil Engineering, Shanghai JiaoTong University Shanghai 200240) 

Received Mar.22, 2007 

Revised Jun.25, 2007  

Abstract  Resonance scattering of elastic spherical shell and cylindrical shell while the surrounding fluid medium has absorption is studied. The normal mode solution derived using exact elastic theory and the separation of variables is still applicable. However, the scattering form function has to be modified for the absorbing medium, otherwise the unreasonable result would be obtained. The backscattering form function in the absorbing medium is redefined, and the form function of elastic spherical and cylindrical shell with vacuum or solid matter filled is calculated in various absorption conditions. The results show that the absorption of surrounding fluid leads to notable attenuation of the coincidence resonances in the mid-frequency, but it has a little influence on the low-frequency resonance scattering induced by the filler inside the shell.　

PACS numbers: 43.20, 43.30