A new coupled computational method in conjunction with three-dimensional finite volume schemes for nonlinear coupled constitutive relations

TL;DR

This paper evaluates a modified nonlinear coupled constitutive relations (NCCR) model using advanced finite volume schemes for three-dimensional hypersonic rarefied gas flows, demonstrating improved accuracy over traditional NSF equations.

Contribution

It introduces a modified NCCR computational approach with finite volume schemes for 3D complex flows, enhancing stability and accuracy in hypersonic rarefied gas simulations.

Findings

Modified NCCR yields results closer to DSMC and experimental data.

Finite volume schemes effectively solve 3D hypersonic rarefied flows.

The approach shows promise for practical high-speed flow applications.

Abstract

Non-equilibrium effects play a vital role in high-speed and rarefied gas flows and the accurate simulation of these flow regimes are far beyond the capability of near-local-equilibrium Navier-Stokes-Fourier equations. Eu proposed generalized hydrodynamic equations which are consistent with the laws of irreversible thermodynamics to solve this problem. Based on Eu's generalized hydrodynamics equations, a computational model, namely the nonlinear coupled constitutive relations(NCCR),was developed by R.S.Myong and applied successfully to one-dimensional shock wave structure and two-dimensional rarefied flows. In this paper, finite volume schemes, including LU-SGS time advance scheme, MUSCL interpolation and AUSMPW+ scheme, are fistly adopted to investigate NCCR model's validity and potential in three-dimensional complex hypersonic rarefied gas flows. Moreover, in order to solve the computational stability problems in 3D complex flows,a modified solution is developed for the NCCR model. Finally, the modified solution is tested for a slip complex flow over a 3D hollow cylinder-flare configuration. The numerical results show that the NCCR model by the modified solution yields good solutions in better agreement with the DSMC results and experimential data than NSF equations, and imply NCCR model's great potential capability in further application.