Comparison of Constant and Discontinuous Quadratic Boundary Elements for Exterior Axisymmetric Acoustic-Wave Propagation Problems

Abstract

The present study involves numerical assessment of two types of boundary elements, namely constant and discontinuous quadratic elements based on a hypersingular Burton and Miller boundary integral formulation to tackle spurious frequencies manifesting in exterior problems. Convergence trends of the two types of boundary element with/without the inclusion of hypersingular formulation were studied for various combinations of boundary conditions and over a wide range of frequencies. The results indicate that discontinuous quadratic elements and constant elements give comparable results, with the quadratic elements being computationally more efficient as they take lesser computational time. Nevertheless, the constant element formulation is easier to implement, and it may be used for solving exterior wave propagation problems.