The development of the pFFT accelerated BEM for 3-D acoustic scattering problems based on the Burton and Millerʹs integral formulation

The precorrected-FFT acceleration technique is successfully applied in the boundary element method for the simulation of 3-D acoustic scattering problems. The composite Helmholtz integral equation presented by Burton and Miller is employed to overcome the nonuniqueness problem occurring in the simulation of exterior acoustic problems by the boundary element method. Since the triangular constant element is employed, the hypersingular boundary integral equation is reduced into a weakly singular boundary integral equation with the application of a modified Burton and Millerʹs formulation. The computational cost, the consumed memory and the convergence of the current method are demonstrated and analyzed through the simulation of a plane acoustic wave scattering from a rigid sphere and from an axisymmetrical rigid structure.