بررسي تأثير روش هاي مختلف فيلتراسيون صريح در LES براي حل عددي نواحي مختلف لايه مرزي آشفته توسعه يافته

Investigation of Various Explicit Filtering Methods in LES for Numerical Solution of Fully Developed Turbulent Boundary Layer

Equations of Large Eddy Simulation are obtained by applying low pass filter on the Navier-Stokes equations. The turbulent modeling in LES depends on the type of the filter function used. In this paper, two explicit filtering methods are compared, using a fully developed turbulent channel flow. First, it is simulated by explicit filtration method applying the smooth Laplace filter. In this case, the subfilter stress term is added to the subgrid model. Good agreements are observed in comparison with Kimʹs DNS results. Second, in order to consider the effects of closeness of explicit filter shape to the cut-off filter, three different filter types were used for the flow simulation. Finally, the abilities of each approach was investigated. Moreover, the regions of boundary layer being more different from each approaches are specified.