A robust CHIEF method for a coupling boundary element method and an equivalent source method

Aiming at the problem of non-uniqueness of solution and singular integral in acoustic boundary element methods, based on the idea of CHIEF methods, the conventional boundary element equation and the equivalent source equation werecombined, and the coupling equivalent relation between the coefficient matrix of the two equations was used to indirectly replace the singular coefficient matrix in the conventional boundary element method, and then a coupled CHIEF method with unique solution in full frequency domain, high computational accuracy and high stability wasproposed. In this method, the equivalent source equation wasused as the supplementary equation, which not only solves the failure of the interior point supplementary equation of the traditional CHIEF method, but also avoids direct calculation of singular integrals by the indirect substitution of matrix, which significantly improves computational efficiency and accuracy. Through typical examples of acoustic radiation and scattering, the proposed method, conventional boundary element method, conventional Burton-Miller method, and equivalent source method werecompared. Results show that not only the unique solution can be obtained in the full wavenumber domain, but also calculation accuracy and efficiency of the proposed method are better than those of the conventional boundary element method and the conventional Burton-Miller method, and the condition number of the coefficient matrix is much lower than that of the equivalent source method. © 2024 Chinese Vibration Engineering Society. All rights reserved.