Sun Min, Zhang Dong, Gong Xiufen
State Key Laboratory of Modern Acoustics, Institute of Acoustics, Nanjing University, Nanjing 210093, China.
Ultrasonics. 2006 Dec 22;44 Suppl 1:e1435-8. doi: 10.1016/j.ultras.2006.05.137. Epub 2006 Jun 6.
A new approach is proposed to study the nonlinear sound field radiated from a concave spherical source with a wide aperture angle. The nonlinear sound field is theoretically described by a set of equations deduced reversely from the second-order Westervelt nonlinear wave equation. To examine the validity of the theoretical model, numerical calculations are performed on a concave spherical radiator with the aperture angle wide up to 40 degrees. Numerical calculation is implemented by the finite difference time domain algorithm in the oblate spheroidal coordinate system. Numerical results are in agreement with those obtained by Kamakura's solutions.
