Acoustic radiation force acting on absorbing spherical shells

The frequency dependence of the acoustic radiation force function, Yp, for an absorbing spherical shell suspended in a plane incident sound field is analysed, in relation to its thickness and the content of its hollow region. The theory is modified to include the effect of hysteresis type of absorption of compressional and shear waves in the material. The results of numerical calculations are presented for two absorbent materials, with the hollow region filled in water or air. These results show (i) how damping (due to absorption), (ii) change of the interior fluid in the shell's hollow region and (iii) and the exterior fluid surrounding the shell affect the acoustic radiation force.