Optimal LES and a New Near-Wall Model for Application to High-Reynolds- Number Air Foils

摘要

Three primary results of research to extend applicability of optimal large eddy simulation (OLES) to general wall-bounded flows are reported. These are: 1) the formulation and testing of theoretically-based OLES, in which theory for multi-point velocity correlations replaces empirical data as input to the model; 2) development of anisotropic models of the two-point correlation for use in wall-bounded OLES; and, 3) generalization and testing of finite- volume OLES formulations to wall-bounded turbulence. It was found that theoretically-based OLES performs very well. The anisotropy representation was formulated in terms of structure tensors, and this also provided a very good representation of the anisotropy in wall-bounded turbulence. But the approach was judged to be too complex for use with the correlations needed in OLES, and a simpler approach is proposed. Finally, the finite-volume OLES for wall- bounded turbulence resulted in a problem that arises from the treatment of the pressure and incompressibility. A new OLES formulation designed to address this has been developed and is being tested.