Density Independent Smoothed Particle Hydrodynamics for Non-Ideal Equation of State

TL;DR

This paper extends a new density-independent SPH method to handle non-ideal equations of state, improving the simulation of hydrodynamical instabilities in complex astrophysical and planetary scenarios.

Contribution

It introduces an extension of the density-independent SPH method to non-ideal EOS, enabling better modeling of hydrodynamical instabilities for diverse materials.

Findings

The new SPH method performs well with non-ideal EOS in standard tests.

It effectively captures hydrodynamical instabilities.

The method is a promising alternative to standard SPH for complex EOS.

Abstract

The smoothed particle hydrodynamics (SPH) method is a useful numerical tool for the study of a variety of astrophysical and planetlogical problems. However, it turned out that the standard SPH algorithm has problems in dealing with hydrodynamical instabilities. This problem is due to the assumption that the local density distribution is differentiable. In order to solve this problem, a new SPH formulation, which does not require the differentiability of the density, have been proposed. This new SPH method improved the treatment of hydrodynamical instabilities. This method, however, is applicable only to the equation of state (EOS) of the ideal gas. In this paper, we describe how to extend the new SPH method to non-ideal EOS. We present the results of various standard numerical tests for non-ideal EOS. Our new method works well for non-ideal EOS. We conclude that our new SPH can handle hydrodynamical instabilities for an arbitrary EOS and that it is an attractive alternative to the standard SPH.