Kategoriarkiv: Script

Parametric Turbine model with OpenFOAM+cfMesh case ready to run

2 svar

I’ve made a parametric turbine case avaliable. Thank’s to my company Minesto for letting me do that.

I’ve done a parametric turbine using Ruby scripting language,
Have set up script for running the entire simulation using cfMesh for volume meshing, OpenFOAM for simulating fields. Openscad for watertunnel-geometry.

geometry simulation

The turbine geometry has pitch as input parameter, you can easily modify to suit your needs.

The simulation has watertunnel size as input parameter.

It’s a steady state MRF model and it runs in 5-10 minutes on a i7-processor. Refine to suit your needs…

 

Case:
turbine_model_bjorn_bergqvist_minesto_ab.tar

Readme file:

Author to this method is Bjorn Bergqvist. Please refer to me or communicate if
you use the turbine geometry model in your work.

Prerequisites:
OpenFOAM 2.?.? (used by 3_run_simulation.sh)
cfMesh (used by 2_create_volume_mesh.sh)
OpenSCAD (used by 2_create_volume_mesh.sh, tunnelfactor 1 is already
generated)
Ruby 2 with spliner gem (for splined pitch, otherwise any Ruby will do)
   (install with: "gem install spliner")

Description of files and directories:
Allrun
   Run through script 1_ to 3_

1_create_geometry.sh
   Not necessary to run. Turbine geometry with pitchmod=0 is
   already generated in geom/turbine.stl.
   Usage: ./1_create_geometry <pitchmod>
   were <pitchmod> is modification of turbine blade pich
   if you are unsure: use pitchmod=0

2_create_volume_mesh.sh
   Usage: ./1_create_volume_mesh.sh <tunnelfactor>
   where <tunnelfactor> is the size of the tunnel where the turbine is simulated
   if you are unsure: use tunnelfactor=1

3_run_simulation.sh
   Usage: ./3_run_simulation.sh <tunnelfactor>
   will run on 4 cpus
   (change in decomposeParDict and 3_run_simulation.sh for other cpu count)

post_moment_table.sh
   Averages moments and forces from 990 to 1000 iterations.

Allclean
   Removes generated mesh and simulation.

turbine_geometry
   The Bjorn Bergqvist(C) turbine geometry.

cfMesh.template
   Directory with files used by cfMesh.

simpleFoam.template
   Directory for simulation (steady state, MRF)

Dirty script for dirty meshes

Lämna ett svar

If you have a messy polyMesh you might use this script. Modify it to suit your needs.

#!/bin/sh
# dirty script for dirty meshes
# author Bjorn Bergqvist
# http://www.discretizer.se
# removes cells which is/have:
# zeroVolumeCells, skewFaces, underdeterminedCells and lowQualityTetFaces
#
# if you have to type something before OpenFOAM commands
# qsub... or somthing
submit=""

# create a batch file for setSet
createBatchFile() {
  counter=0
  echo "cellSet cellsToKeep new" > $2
  for i in `grep Writing $1 |awk '{ print $NF }'`
    do

      if [ $i == "zeroVolumeCells" ]; then
        echo "cellSet cellsToKeep add cellToCell zeroVolumeCells any" >> $2
        echo `grep $i log.checkMesh`
        counter=$((counter+1)) 
      fi
      if [ $i == "skewFaces" ]; then
        echo "cellSet cellsToKeep add faceToCell skewFaces any" >> $2
        echo `grep $i log.checkMesh`
        counter=$((counter+1)) 
      fi
      if [ $i == "underdeterminedCells" ]; then
        echo "cellSet cellsToKeep add cellToCell underdeterminedCells any" >> $2
        echo `grep $i log.checkMesh`
        counter=$((counter+1)) 
      fi
      if [ $i == "lowQualityTetFaces" ]; then
        echo "cellSet cellsToKeep add faceToCell lowQualityTetFaces any" >> $2
        echo `grep $i log.checkMesh`
        counter=$((counter+1)) 
      fi
    done
    echo "cellSet cellsToKeep invert" >> $2
    echo "cellSet cellsToKeep subset" >> $2
    echo "quit" >> $2
    return $counter
}

logfile=log.txt
echo "" > $logfile

while :
do
  $submit checkMesh -allGeometry -allTopology -latestTime > log.checkMesh
  checkString=`grep 'The mesh has multiple regions' log.checkMesh`
  if [ ! ${#checkString} == 0 ]; then
    echo "multiple regions: splitMeshRegions"
    $submit splitMeshRegions -largestOnly >> $logfile
    $submit subsetMesh -overwrite region0 >> $logfile
    $submit createPatch -overwrite >> $logfile
    echo "rerun checkMesh"
    $submit checkMesh -allGeometry -allTopology -latestTime > log.checkMesh
  fi
  createBatchFile log.checkMesh batchForDeleting
  fileOk=$?
  echo "fileOk $fileOk"
  if [ $fileOk == 0 ]; then
    echo "nothing to do"
    exit 0
  fi
  $submit setSet -latestTime -batch batchForDeleting > $logfile
  $submit subsetMesh cellsToKeep >> $logfile
  $submit createPatch -overwrite >> $logfile
done

Typical output:

<<Writing 4 zero volume cells to set zeroVolumeCells
<<Writing 232 skew faces to set skewFaces
<<Writing 118 faces with low quality or negative volume decomposition tets to set lowQualityTetFaces
<<Writing 3806 under-determined cells to set underdeterminedCells
fileOk 4
multiple regions: splitMeshRegions
rerun checkMesh
<<Writing 114 skew faces to set skewFaces
<<Writing 1732 under-determined cells to set underdeterminedCells
fileOk 2
multiple regions: splitMeshRegions
rerun checkMesh
<<Writing 6 skew faces to set skewFaces
<<Writing 608 under-determined cells to set underdeterminedCells
fileOk 2
multiple regions: splitMeshRegions
rerun checkMesh
<<Writing 247 under-determined cells to set underdeterminedCells
fileOk 1
multiple regions: splitMeshRegions
rerun checkMesh
<<Writing 125 under-determined cells to set underdeterminedCells
fileOk 1
<<Writing 72 under-determined cells to set underdeterminedCells
fileOk 1
<<Writing 44 under-determined cells to set underdeterminedCells
fileOk 1
<<Writing 27 under-determined cells to set underdeterminedCells
fileOk 1
<<Writing 20 under-determined cells to set underdeterminedCells
fileOk 1
<<Writing 12 under-determined cells to set underdeterminedCells
fileOk 1
<<Writing 5 under-determined cells to set underdeterminedCells
fileOk 1
<<Writing 3 under-determined cells to set underdeterminedCells
fileOk 1
<<Writing 1 under-determined cells to set underdeterminedCells
fileOk 1
<<Writing 1 under-determined cells to set underdeterminedCells
fileOk 1
fileOk 0
nothing to do