Artificial viscosity in simulation of shock waves by smoothed particle hydrodynamics

TL;DR

This paper revisits artificial viscosity in smoothed particle hydrodynamics, proposing a time-variable coefficient to improve shock wave simulation accuracy and prevent unphysical effects, validated through computational experiments.

Contribution

It introduces a modified artificial viscosity with a time-variable coefficient and a restriction to enhance shock wave simulation in SPH methods.

Findings

The modified viscosity effectively prevents inter-particle penetration.

It reduces unwanted heating and unphysical solutions.

Computational results confirm the approach's accuracy.

Abstract

The artificial viscosity is reconsidered in smoothed particle hydrodynamics to prevent inter-particle penetration, unwanted heating, and unphysical solutions. The coefficients in the Monaghan's standard artificial viscosity are considered as time variable, and a restriction on them is proposed such that avoiding the undesired effects in the subsonic regions. The shock formation in adiabatic and isothermal cases are used to study the ability of this modified artificial viscosity recipe. The computer experiments show that the proposal appears to work and the accuracy of this restriction is acceptable.