A Few Benchmark Test Cases for Higher-order Euler Solvers

TL;DR

This paper introduces diverse benchmark test cases with complex wave interactions for evaluating higher-order Euler schemes, using a new fourth-order gas-kinetic scheme as a reference for validation.

Contribution

It provides a set of simple, versatile test cases with reference solutions for assessing and improving higher-order numerical schemes for Euler equations.

Findings

The test cases include oscillatory solutions and large density ratios.

The GKS provides reliable reference solutions for various wave interactions.

These benchmarks facilitate validation and development of advanced CFD schemes.

Abstract

There have been great efforts on the development of higher-order numerical schemes for compressible Euler equations. The traditional tests mostly targeting on the strong shock interactions alone may not be adequate to test the performance of higher-order schemes. This study will introduce a few test cases with a wide range of wave structures for testing higher-order schemes. As reference solutions, all test cases will be calculated by our recently developed two-stage fourth-order gas-kinetic scheme (GKS). All examples are selected so that the numerical settings are very simple and any high order accurate scheme can be straightly used for these test cases, and compare their performance with the GKS solutions. The examples include highly oscillatory solutions and the large density ratio problem in one dimensional case; hurricane-like solutions, interactions of planar contact discontinuities (the composite of entropy wave and vortex sheets) sheets with large Mach number asymptotic, interaction of planar rarefaction waves with transition from continuous flows to the presence of shocks, and other types of interactions of two-dimensional planar waves. The numerical results from the fourth-order gas-kinetic scheme provide reference solutions only. These benchmark test cases will help CFD developers to validate and further develop their schemes to a higher level of accuracy and robustness.