Suitability of Low-order Numerical Schemes in Large Eddy Simulations

Several low-order numerical schemes were evaluated for their suitability in large-eddy simulations based on 3D Taylor-Green vortex, with and without a subgrid-scale model. It shows that dissipation characteristics of three numerical schemes used are similar to a subgrid-scale model. At lower Reynolds numbers, flow fields are relatively smooth, numerical dissipation is lower; As Reynolds number increasing, transition to turbulence occurs and numerical dissipation grows greatly. For MUSCL and bounded centered schemes, subgrid-scale model has a little influence on results at high Reynolds numbers. The second-order central scheme exhibits lower dissipation, but at higher Reynolds numbers numerical dissipation still dominates total energy dissipation of flow. With an explicit subgrid-scale model the results even become worse. Therefore, for large eddy simulations in engineering, the second order central scheme is suitable, particularly without an explicit subgrid-scale model.