Smoothed corners and scattered waves

TL;DR

This paper presents a local, efficient method for smoothing corners on curves and surfaces, which preserves geometric features and reduces computational costs in acoustic scattering simulations.

Contribution

The authors introduce a novel, explicit smoothing technique for geometric singularities that maintains important features and improves computational efficiency in wave scattering problems.

Findings

Smoothed geometries lead to reduced computational costs.

The error in scattered fields is proportional to the size of the smoothed region.

The method preserves convexity and symmetry of the original shape.

Abstract

We introduce an arbitrary order, computationally efficient method to smooth corners on curves in the plane, as well as edges and vertices on surfaces in $\mathbb R^3$. The method is local, only modifying the original surface in a neighborhood of the geometric singularity, and preserves desirable features like convexity and symmetry. The smoothness of the final surface is an explicit parameter in the method, and the bandlimit of the smoothed surface is proportional to its smoothness. Several numerical examples are provided in the context of acoustic scattering. In particular, we compare scattered fields from smoothed geometries in two dimensions with those from polygonal domains. We observe that significant reductions in computational cost can be obtained if merely approximate solutions are desired in the near- or far-field. Provided that it is sub-wavelength, the error of the scattered field is proportional to the size of the geometry that is modified.