LES ============== More detailed results of the demonstration examples can be found in the following references: .. seealso:: `Xiao, Maochao, Alessandro Ceci, Pedro Costa, Johan Larsson, and Sergio Pirozzoli. "CaLES: A GPU-accelerated solver for large-eddy simulation of wall-bounded flows." Computer Physics Communications 310 (2025) 109546. `_ Wall-resolved turbulent plane channel flow ----------------------------------------------------- This case corresponds to ``example/les/_manuscript_turbulent_channel``. This example simulates a fully developed turbulent plane channel flow using WRLES. The simulation employs two subgrid-scale models: the classical Smagorinsky model and the dynamic Smagorinsky model. - **Domain size**: `(Lx, Ly, Lz) = (12.8h, 2.0h, 4.8h)`, where `h` is the channel half-height. - **Boundary conditions**: No-slip boundary condition in the y-direction and periodic boundary conditions in the `x` and `z` directions. - **Reynolds number**: `Reτ = 20,000`, with a friction coefficient `Cf = 0.00591`. - **Grid resolution**: Four different grids are used for a grid convergence study, with the wall-normal grid spacing varying from approximately `40+` to `10+`, maintaining an aspect ratio `AR = ∆x/∆z = 1.8`. The following figure shows the visualization of the turbulent channel flow obtained with WRLES: .. figure:: figure/WR_channel_flow.png :width: 60% :align: center **Figure 1:** Visualization of turbulent channel flow obtained with WRLES The following figure presents the profiles of mean streamwise velocity, resolved turbulent normal stress and shear stress .. figure:: figure/WR_channel_flow_mean.png :width: 100% :align: center **Figure 2:** Mean streamwise velocity profiles with WRLES using SM (a) and DSM (b) .. figure:: figure/WR_channel_flow_resolved.png :width: 100% :align: center **Figure 3:** Resolved turbulent normal and shear stress profiles with WRLES using SM (a,c) and DSM (b,d). Line codes: ⟨uu⟩ (solid), ⟨vv⟩ (dashed), ⟨ww⟩ (dash-dotted). Wall-modeled turbulent plane channel flow ----------------------------------------------------- This case corresponds to ``example/les/_manuscript_turbulent_channel_wall_model``. This example simulates a fully developed turbulent plane channel flow using WMLES. The simulation employs two subgrid-scale models: the classical Smagorinsky model and the dynamic Smagorinsky model. - **Domain size and boundary conditions**: The domain size and boundary conditions are the same as those used in the WRLES case. - **Reynolds number**: `Reτ = 250,000`, with a friction coefficient `Cf = 0.00344`. - **Grid resolution**: Thirteen different grids are used for a grid convergence study, with the wall-normal grid spacing varying from approximately `0.1h` to `0.006h`. The aspect ratio is `AR = 1.0` and `2.0`. - **Wall-modeling layer thickness**: The wall-modeling layer thickness is set to `hwm = 0.1h`. The following figure shows the visualization of the turbulent channel flow obtained with WMLES: .. figure:: figure/WM_channel_flow.png :width: 60% :align: center **Figure 4:** Visualization of turbulent channel flow obtained with WRLES The following figure presents the profiles of mean streamwise velocity, resolved turbulent normal stress and shear stress .. figure:: figure/WM_channel_flow_mean.png :width: 100% :align: center **Figure 5:** Mean streamwise velocity profiles with WMLES using the SM (a,c) and DSM (b,d) models on the grids with `AR = 1.0` (a,b) and `AR = 2.0` (c,d). .. figure:: figure/WM_channel_flow_resolved.png :width: 100% :align: center **Figure 6:** Resolved turbulent normal stress (a,b) and shear stress (c,d) obtained with WMLES using the SM (a,c) and DSM (b,d) models on the grids with `AR = 1.0`. Line codes: ⟨uu⟩ (solid), ⟨vv⟩ (dashed), ⟨ww⟩ (dash-dotted). Wall-modeled turbulent square duct flow ------------------------------------------------- This case corresponds to ``example/les/_manuscript_turbulent_duct_wall_model``. This example simulates a fully developed turbulent flow in a square duct using WMLES. The simulation employs two subgrid-scale models: the classical Smagorinsky model and the dynamic Smagorinsky model. - **Domain size**: `(Lx, Ly, Lz) = (12.8h, 2.0h, 2.0h)`, where `h` is half the side length of the duct. - **Boundary conditions**: Wall-modeled boundary conditions are applied in the `y` and `z` directions, with periodic boundary conditions in the `x` direction. - **Reynolds number**: `Reτ = 40,000`, with a friction coefficient `Cf = 0.00557`. - **Grid resolution**: Six different grids are used for a grid convergence study, with the wall-normal grid spacing varying from approximately `0.1h` to `0.006h`. - **Wall-modeling layer thickness**: The wall-modeling layer thickness is set to `hwm = 0.1h`. The following figure shows the visualization of the square duct flow obtained with WMLES: .. figure:: figure/WM_duct_flow.png :width: 100% :align: center **Figure 7:** Visualization of turbulent channel flow obtained with WRLES The following figure presents the profiles of mean streamwise velocity, resolved turbulent normal stress and shear stress .. figure:: figure/WM_duct_mean.png :width: 100% :align: center **Figure 8:** Mean streamwise velocity profilesalong the wall bisector (a,b) and corner bisector (c,d) obtained from WMLES with the SM (a,c) and DSM (b,d) models. .. figure:: figure/WM_duct_resolved.png :width: 100% :align: center **Figure 9:** Resolved turbulent normal stress (a,b) and shear stress (c,d) along the wall bisector as obtained from WMLES with the SM (a,c) and DSM (b,d) models. Line codes: ⟨uu⟩ (solid), ⟨vv⟩ (dashed), ⟨ww⟩ (dash-dotted).