Rapid Optimal SPH Particle Distributions in Spherical Geometries For Creating Astrophysical Initial Conditions

TL;DR

This paper introduces two algorithms for generating evenly distributed particle arrangements on spherical surfaces, enabling the creation of astrophysical initial conditions with optimal volume partitioning and improved stability in SPH simulations.

Contribution

The paper presents novel algorithms for distributing particles on spheres that optimize volume partitioning and stability, especially for multi-material astrophysical objects.

Findings

Algorithms outperform stretched lattice arrangements in stability and conformity

Method effectively models multi-material spheres like planets with core-mantle boundaries

Enhanced simulation accuracy for astrophysical initial conditions

Abstract

Creating spherical initial conditions in smoothed particle hydrodynamics simulations that are spherically conformal is a difficult task. Here, we describe two algorithmic methods for evenly distributing points on surfaces, that when paired can be used to build 3D spherical objects with optimal equipartition of volume between particles, commensurate with an arbitrary, radial density function. We demonstrate the efficacy of our method against stretched lattice arrangements on the metrics of hydrodynamic stability, spherical conformity, and the harmonic power distribution of gravitational settling oscillations. We further demonstrate how our method is highly optimized for simulating multi-material spheres, such as planets with core-mantle boundaries.