Assessing OpenFOAM-based Large-eddy Simulation Using Decay Characteristics of An Isotropic Taylor-green Vortex

Abstract

The aim of this study is to investigate OpenFOAM using isotropic TGV flows. The main focus is on the establishment of energy conservation laws, in particular using inviscid fields to assess energy constancy; Large-Eddy Simulation (LES) is applied and the results are compared with those obtained using spectral methods; unlike previous studies of OpenFOAM, this study uses an unsteady turbulent TGV flow. The computational methods used are a central difference method, a PISO algorithm and a Smagorinsky model. The study revealed errors in the conservation of kinetic energy in the OpenFOAM analysis. In particular, the energy decay was significant at high spatial resolution, confirming the different turbulence energy decay characteristics of DNS and OpenFOAM. However, when the model constant was 0.6, the decay characteristics were shown to be in good agreement with DNS.