High-Frequency Voronoi Noise Reduced by Smoothed Mesh Motion

TL;DR

This paper introduces a smoothing technique for mesh motion in hydrodynamics codes with moving Voronoi meshes, significantly reducing high-frequency grid noise and improving simulation stability.

Contribution

The paper presents a novel smoothing approach for mesh velocities that mitigates grid noise in moving Voronoi mesh hydrodynamics codes.

Findings

Reduced high-frequency noise in simulations

Improved stability and accuracy of hydrodynamics codes

Effective in multiple test scenarios

Abstract

We describe a technique for improving the performance of hydrodynamics codes which employ a moving Voronoi mesh. Currently, such codes are susceptible to high-frequency noise produced by rapid adjustments in the grid topology on the smallest scales. The treatment for this grid noise is simple; instead of moving the mesh-generating marker points with the local fluid velocity, this velocity field is smoothed on small scales, so that neighboring marker points generally have similar velocities. We demonstrate significant improvement gained by this adjustment in several code tests relevant to the physics which moving-mesh codes are designed to capture.