A NOVEL TECHNIQUE IN BOUNDARY INTEGRAL EQUATIONS FOR ANALYZING ACOUSTIC RADIATION FROM AXISYMMETRIC BODIES

A novel technique is suggested to avoid singular integrals of boundary integral equations (BIE) for exterior sound radiation problems. The technique, reproduction of diagonal terms (RDT), utilizes special solutions of some monopole sources, which give the distribution of theoretical surface pressure and velocity to reproduce diagonal terms in the BIE matrices. It is proposed to employ three monopole sources in reproduction of diagonal terms in both pressure and velocity matrices. Although the interior points are applied to generate monopole solutions, the concept is basically different from that of general interior Helmholtz equations. So the present technique is different from those traditional methods to improve BIE method through added interior Helmholtz equations. Several examples are presented to demonstrate the effectiveness of the proposed technique for closed axisymmetric surfaces. Numerical results show that the technique of RDT can improve the accuracy of the solution up to 10 times compared to the conventional techniques such as SHF, CHIEF-SHF.