High-order discretization of a stable time-domain integral equation for 3D acoustic scattering
This work provides a high-order accurate and stable numerical method for time-domain acoustic scattering, which is important for computational acoustics and wave propagation problems.
The authors developed a high-order explicit method for 3D acoustic scattering using a combined-field time-domain integral equation, achieving 5-9 digits of accuracy with up to 8th order and 20,000 spatial unknowns on torus geometries.
We develop a high-order, explicit method for acoustic scattering in three space dimensions based on a combined-field time-domain integral equation. The spatial discretization, of Nyström type, uses Gaussian quadrature on panels combined with a special treatment of the weakly singular kernels arising in near-neighbor interactions. In time, a new class of convolution splines is used in a predictor-corrector algorithm. Experiments on a torus and a perturbed torus are used to explore the stability and accuracy of the proposed scheme. This involved around one thousand solver runs, at up to 8th order and up to around 20,000 spatial unknowns, demonstrating 5-9 digits of accuracy. In addition we show that parameters in the combined field formulation, chosen on the basis of analysis for the sphere and other convex scatterers, work well in these cases.