Large Eddy Simulation of a Muffler with the High-Order Spectral Difference Method

Abstract

The combination of the high-order accurate spectral difference discretization on unstructured grids with subgrid-scale modelling is investigated for large eddy simulation of a muffler at Re = 4.64 · 10 4 and low Mach number. The subgrid-scale stress tensor is modelled by the wall-adapting local eddy-viscosity model with a cut-off length which is a decreasing function of the order of accuracy of the scheme. Numerical results indicate that although the highorder solver without subgrid-scale modelling is already able to capture well the features of the flow, the coupling with the wall-adapting local eddy-viscosity model improves the quality of the solution.

Entropy stable wall boundary conditions for the three-dimensional compressible Navier–Stokes equations

“…In computational fluid dynamics (CFD), next generation numerical algorithms for use in large eddy simulations (LES) and hybrid Reynolds-averaged Navier-Stokes (RANS)-LES simulations will undoubtedly rely on efficient high-order accurate formulations (see, for instance, [2,3,4,5,6,7,8,9,10,11,12,13,14,15]). Although high order techniques are well suited for smooth solutions, numerical instabilities may occur if the flow contains discontinuities or under-resolved physical features.…”

“…, i = 1, 2, 3, are the inviscid and viscous grid fluxes, respectively. 10 The 9 The 3D compressible Navier-Stokes equations form a system of five non-linear PDEs 10. Recall that the vectors with an over-bar are defined at the flux points.…”

“…The 3D compressible Navier-Stokes equations form a system of five non-linear PDEs 10. Recall that the vectors with an over-bar are defined at the flux points.…”