An improved anisotropy-resolving subgrid-scale model with the aid of a scale-similarity modeling concept

An improved subgrid-scale (SGS) model was proposed by combining an isotropic linear eddy-viscosity term with an extra anisotropic term. In the present study, primary attention was given to maintaining the computational stability while improving the predictive performance particularly for coarse grid resolution in the near-wall region. For the extra anisotropic term used for this purpose, the present study introduced a residual term after subtracting an eddy-viscosity form from the Bardina SGS-Reynolds-stress model [Bardina, J., Ferziger, J.H., Reynolds, W.C., 1980. Improved subgrid scale models for large eddy simulation. AIAA Paper 80-1357]. The resultant extra term yields no undesirable extra energy transfer between the grid-scale and SGS components that could cause numerical instability under coarse grid conditions. Therefore, this extra term is not expected to have any serious negative effects on the computational stability. In order to assess the performance, the proposed model was applied to the numerical simulation of fully-developed plane channel flows with various grid resolutions and at various Reynolds numbers. The computational results were considerably improved by the present SGS model and detailed investigations of the obtained results indicated the usefulness of the present model for engineering applications.