Backstep flow

Update: June 1, 2017
OpenFOAM 4.x

Case directory

$FOAM_TUTORIALS/incompressible/pisoFoam/les/pitzDaily

Summary

The fluid flows in from the region "inlet" at (10, 0, 0) m/s and out from the region "outlet". No-slip condition is set to the walls of the flow channel, and the problem is solved as 2-dimensional problem with a single mesh in the Z-direction. LES (Eddy viscosity model is dynamic one-equation) is used for turbulence calculation.

Model geometry Model geometry

The meshes are as follows.

Mesh Meshes

The pressure at each time at the specified coordinates is output using the probes function, and the flow velocity at each time on the specified surface is output using the surfaceSampling function, under the postProcessing directory. Using the fieldAverage function, the time averages of the pressure and velocity are output as pMean and UMean for each time. These settings are made in system/controlDict.

The calculation result is as follows.

Flow velocity (U)
Flow velocity (U) Flow velocity (U)
Pressure (p) Pressure (p)
Time-averaged flow velocity at the final time (UMean) Time-averaged flow velocity at the final time (UMean)
Time-averaged pressure at the final time (pMean) Time-averaged pressure at the final time (pMean)
Time history of pressure at coordinates (0.0254, 0.0253, 0) (Probe 0) Time history of pressure at coordinates (0.0254, 0.0253, 0) (Probe 0)

Commands

cp -r $FOAM_TUTORIALS/incompressible/pisoFoam/les/pitzDaily pitzDaily
cd pitzDaily

blockMesh
pisoFoam

# 3D visualization
paraFoam

# Visulalize the probes function results
gnuplot
gnuplot>set xrange[0:0.1]
gnuplot>set yrange[-1500:1500]
gnuplot>plot "postProcessing/probes/0/p" using 1:2 title 'Probe 0' with lines lc rgb "grey"

Calculation time

13 minutes 34.47 seconds *Single, Inter(R) Core(TM) i7-2600 CPU @ 3.40GHz 3.40GHz

Reference

  • Kim, W and Menon, S. (1995). A new dynamic one-equation subgrid-scale model for large eddy simulation. In 33rd Aerospace Sciences Meeting and Exhibit, Reno, NV, 1995.