Evaluation of high order smooth filter in large eddy simulation of fully developed turbulent channel flow with explicit filtering

Explicit filtering with a smooth shape is one of approaches adopted in large eddy simulations (LES). The present work investigates the application of an explicit high order smooth (HOS) filter for the LES of a fully developed turbulent channel flow. The Crank-Nicolson scheme for time marching and second-order finite-volume schemes for spatial derivatives were implemented in this investigation. Implicit filtering, together with the Smagorinsky sub-grid scale (SGS) model, and explicit filtering, along with a HOS filter were studied in a fully turbulent channel flow. In this study, explicit HOS filtering with an explicit filter width to grid size ratio of 2.0 was in agreement with the available direct numerical simulation (DNS) data. However, the mean velocity profile in the streamwise direction was underestimated, and the turbulence intensity in the streamwise direction improved compared to other directions. Moreover, turbulence stresses were well predicted using the mixed SGS and sub-filter stress (SFS) models and applying the HOS filter as an explicit filter.