Performance of a hybrid LES/RANS model combined with a wall function for predicting quite high Reynolds-number turbulent channel flows up to Reτ=6×107

Abstract

Performance of an anisotropy-resolving hybrid LES/RANS (HLR) model was investigated. An important feature of this HLR model is the introduction of an extra anisotropic term in a sub-grid scale (SGS) model for large eddy simulation (LES) to represent the SGS stress anisotropy more correctly. Although the basic performance of this model was validated in some previous studies, it is still unclear how the model works for very high Reynolds-number (Re) turbulent flows, in which no-slip wall conditions are no more applicable. Thus, to investigate the predictive performance of this HLR model, it was applied to very high Re turbulent channel flows up to Reτ = 6 × 107, together with a conventional wall function as the wall-boundary condition. The computational results obtained by the present anisotropic HLR model were carefully compared with those by an isotropic HLR model.

Keywords

• turbulence
• anisotropy-resolving sgs model
• hybrid les/rans model
• high reynolds number
• wall function