Backstep flow

Update: June 1, 2017
OpenFOAM 4.x

Case directory

$FOAM_TUTORIALS/incompressible/simpleFoam/pitzDaily

Summary

The fluid flows in from the region "inlet" at (10, 0, 0) m/s and out from the region "outlet". A no-slip condition is set for the channel walls, and the problem is solved in 2 dimensions with a single mesh in the Z direction. The standard k-ε model is used as the turbulence model.

Model geometry Model geometry

The meshes are as follows.

Mesh Meshes

We use the streamlines function to draw streamlines during the calculation. The configuration file is system/streamlines, which is referenced in system/controlDict as shown below.

nLines  10;
start   (-0.0205 0.001  0.00001);
end     (-0.0205 0.0251 0.00001);
fields  (p k U);

// Must be last entry
#includeEtc "caseDicts/postProcessing/visualization/streamlines.cfg"

The streamline data is saved as a vtk format file under the directory postProcessing/sets at each time. This file can be loaded into ParaView to visualize the streamlines.

To visualize the calculated turbulence energy and turbulence dissipation rate, check "k" and "epsilon" in the "Properties" tab in ParaView.

Check k and epsilon Check "k" and "epsilon"

The calculation result is as follows.

Flow velocity (U) Flow velocity (U)
Pressure (p) Pressure (p)
Turbulent energy (k) Turbulent energy (k)
Turbulent dissipation rate (epsilon) Turbulent dissipation rate (epsilon)
Streamlines by streamlines function Streamlines by streamlines function

Commands

cp -r $FOAM_TUTORIALS/incompressible/simpleFoam/pitzDaily pitzDaily
cd pitzDaily

blockMesh
simpleFoam

paraFoam

Calculation time

12.04 seconds *Single, Inter(R) Core(TM) i7-2600 CPU @ 3.40GHz 3.40GHz

Reference