Integral equation methods with unique solution for all wavenumbers applied to acoustic radiation

Abstract

The acoustic exterior Neumann problem is solved using an easy process based upon the boundary element method and able to eliminate effects of irregular frequencies in time harmonic domain. This technique is performed as follows: (i) two computations are done around the characteristic frequency, decreased and increased by a small imaginary part; (ii) average between pressures at these two frequencies ensures unique solution for all wavenumbers. This method is numerically tested for an infinite cylinder, an axisymmetric cylinder, a sphere and a three-dimensional cat’s eye structure. This work highlights ease and efficiency of the technique under consideration to remove the irregular frequencies effects.