Low-diffusion approximate Riemann solvers for Reynolds-stress transport

JOURNAL OF COMPUTATIONAL PHYSICS

卷:268

Article

Ben Nasr, N.¹  Gerolymos, G. A.¹  Vallet, I.¹ 

[1] Univ Paris 06, F-75005 Paris, France

关键词: Compressible RANS;    Reynolds-stress model;    Approximate Riemann solver;    Low-diffusion fluxes;   

DOI  :  10.1016/j.jcp.2014.02.010

来源: Elsevier

【 摘 要 】

The paper investigates the use of low-diffusion (contact-discontinuity-resolving) approximate Riemann solvers for the convective part of the Reynolds-averaged Navier-Stokes (RANs) equations with Reynolds-stress model (RSM) for turbulence. Different equivalent forms of the RSM-RANS system are discussed and classification of the complex terms introduced by advanced turbulence closures is attempted. Computational examples are presented, which indicate that the use of contact-discontinuity-resolving convective numerical fluxes, along with a passive-scalar approach for the Reynolds-stresses, may lead to unphysical oscillations of the solution. To determine the source of these instabilities, theoretical analysis of the Riemann problem for a simplified Reynolds-stress transport model-system, which incorporates the divergence of the Reynolds-stress tensor in the convective part of the mean-flow equations, and includes only those nonconservative products which are computable (do not require modelling), was undertaken, highlighting the differences in wave-structure compared to the passive-scalar case. A hybrid solution, allowing the combination of any low-diffusion approximate Riemann solver with the complex tensorial representations used in advanced models, is proposed, combining low-diffusion fluxes for the mean-flow equations with a more dissipative massflux for Reynolds-stress-transport. Several computational examples are presented to assess the performance of this approach, demonstrating enhanced accuracy and satisfactory convergence. (C) 2014 Elsevier Inc. All rights reserved.

【 授权许可】

Free