Smoothed corners and scattered waves
For computational acoustics, this method offers a practical way to approximate scattering from polygonal domains with reduced cost, though it is an incremental improvement over existing smoothing techniques.
The paper introduces a local, arbitrary-order method to smooth corners on curves and surfaces, preserving convexity and symmetry. In acoustic scattering, the method reduces computational cost for approximate near- or far-field solutions, with error proportional to the modified region size when sub-wavelength.
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.