|
Large Eddy Simulation and Detached Eddy Simulation Studies of Flow and Mass Exchange Processes Between a Channel and a Cavity Filled with a Neutrally Buoyant or a Dense Miscible Contaminant. 1) General sketch of flow in a channel with a bottom 2D cavity. The mesh size is close to 14 million cells (320*224*192 in the streamwise, vertical and spanwise directions). For the 2D simulations a mesh of 640*448 cells was used. Reynolds number in the channel close to 20,000 cavity Reynolds number Re.= 3,300.
2) Mean velocity profiles for 3D LES simulations with turbulent (corresponding to conditions in the experiment of Pereira and Sousa swown with the symbols) and laminar inflow. x/h measured from leading edge cavity corner..
3) Coherent structures visualized using Q criterion for laminar and turbulent inflow 3D LES simulations.
4) Animation showing the spanwise vorticity contours for the laminar inflow case in an xy plane (3D LES) Xyplane_m8p5adv_lrain_laminar.avi
5) Animation showing the spanwise vorticity contours for the turbulent inflow case in an xy plane (3D LES) Xyplane_m8p5adv_lrain_turbulent.avi
6) Instantaneous vorticity magnitude contours in laminar and turbulent inflow cases (3D LES). a) plane parallel to bottom channel situated at y/D=0.05 from it; b) xy plane c) spanwise plane cutting through middle of cavity
7) Vertical velocity power spectra at different stations for laminar and turbulent 3D LES simulations. Points position shown in the inset
8) Visualization of the removal of non-buoyant contaminant for laminar and turbulent inflow conditions using 3D LES.
9) Mean streamwise velocity contours corresponding to unsteady RANS, SA and SST based DES (with/without turbulent inflow fluctuations) and 3D LES with turbulent inflow conditions
10) Comnparison of non-buoyant scalar removal between URANS, DES and 3D LES
11) Visualization of the removal of negatively buoyant contaminant (Richardson number=0.4) using 2D LES.
12) Visualization of the removal of negatively buoyant contaminant (Richardson number=0.2) using 2D LES.
13) Contaminant flux dependence on the Richardson number (2D LES). a) flux through cavity top (left); b) flux through x=2.25D plane downstream the cavity (right).
|
