Large-Eddy Simulation of Turbulent Channel Flow with OpenFOAM

Abstract

This article presents the results of large-eddy simulations (LES) of fully developed turbulent channel flow at Re_τ ≈ 1000 using OpenFOAM solvers. The purpose of the work is two-fold. One is to provide publicly available validation results for an important LES benchmark, together with the case setup and codes used for post-processing. The second is to serve as an entry point for those starting out with scale-resolving simulations of turbulence with OpenFOAM. To that end, the exposition of the material is somewhat lengthier and more pedagogical than in a typical scientific paper. The simulations cover a range of grid resolutions to demonstrate the sensitivity of the predictive accuracy to the cell size. Furthermore, the results from the implicit LES are compared with those obtained using the Sigma subgrid-scale model. The post-processing aims to cover most quantities typically considered in the analysis of a turbulent flow, including velocity statistics up to fourth order, fluctuations of vorticity, spatial spectra and two-point correlations, linear spectral coherence, and the budget of the turbulent kinetic energy. To facilitate the analysis, we draw on both built-in OpenFOAM capabilities and community contributions. The results show that upon sufficient resolution of the inner scales, OpenFOAM accurately simulates wall-bounded turbulence, showing excellent agreement with reference data from direct numerical simulations. However, explicit subgrid scale modelling fails to improve the simulations’ accuracy.