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Wall modeling les approach on smooth wall from low to high reynolds numbers

Both cases show good agreement with the experiment or DNS result comparing to the pure LES mesh without wall modeling. The wall modeling LES approach could be used as a novel boundary layer simulation approach to avoid high computational cost. | Journal of Automation and Control Engineering Vol. 4, No. 4, August 2016 Wall Modeling LES Approach on Smooth Wall From Low to High Reynolds Numbers Yu Liu and Mingbo Tong College of Aerospace and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China Email: liuyuyyyy@126.com, tongw@nuaa.edu.cn wall and estimates the instantaneous shear stress τw at the wall y=0. This is then given back to the LES as a boundary condition. Abstract—A wall modeling LES approach is achieved for the smooth wall boundary layer simulation. By this method, the motions in the inner boundary layer will be modeled by a uniform wall modeling mesh using an equilibrium equation. After getting the feedback of wall shear stress from the wall-model, LES mesh will recalculate the flow field so that a low resolution mesh can be used for LES on wall bounded flow from low Reynolds number to high. Two cases, Re=3300 and 30000, are set up to verify the wallmodel approach. Both cases show good agreement with the experiment or DNS result comparing to the pure LES mesh without wall modeling. The wall modeling LES approach could be used as a novel boundary layer simulation approach to avoid high computational cost.1 II. The inner layer wall model is a filtered equation [3]. Assuming equilibrium, the unresolved inner layer is modeled by solving d dη INTRODUCTION When applied to turbulent boundary layers at high Reynolds numbers, the computational cost of large eddy simulation (LES) becomes highly prohibitive. Boundary layers are multi-scale phenomena where the energetic and dynamically important motions in the inner layer, 10% of the boundary layer, become progressively smaller in size as the Reynolds number increases, while the size of energetic motions in the outer layer is nearly independent of Reynolds number. If these inner layer motions are resolved, the required grid resolution necessarily scales with the viscous length scale. Therefore, in order to make LES applicable