OpenFOAM/C3/Using-PyFoam-Utilities/English

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Tutorial : 22

Name : Using PyFoam Utilities

Script : Anmol Sahoo and Rahul Joshi

Narration : Rahul Joshi

Keywords : OpenFOAM, PyFoam, CFD, Linux, PyFoam utilities,shockTube


Visual Cue
Narration
Show Slide : Title Welcome to the spoken tutorial on Using PyFoam Utilities
Show Slide : Learning Objectives In this tutorial we will learn :
  • About PyFoam Utilities
  • How to use PyFoam Utilites
  • How to run and plot data for the shockTube case using PyFoam Utilites
Show Slide :

System Requirement

To record this tutorial I am using:
  • Ubuntu Linux Operating System 14.04
  • OpenFOAM v2.3.0
  • PyFoam 0.6.5
Show Slide :

Pre-requisite

As a prerequisite user should have :
  • basic knowledge of running commands on the Linux terminal
  • And some experience of running and analyzing OpenFOAM cases
Show slide : Introduction to PyFoam Utilities Let me introduce you to PyFoam utilities.


  • Utilities are Python programs which come inbuilt with PyFoam.
  • Each utility has a specific function.
  • Utilities are executed from the command line.
Show slide : List of Utilities List of utilites that can be viewed using tab completion
Open terminal. Type pyFoam and press Tab twice Open the terminal.


The list of utilities can be viewed by

  • typing pyFoam
  • and then pressing Tab key twice
Show slide : List of utilities Let me switch back to the slides.

Each utility can be executed with the –help option.


This helps us to find out what it does and what its options are.

Show Slide : using utilties


We are going to use the following PyFoam Utilities to run the Shock Tube case.


We will use -

  • PyFoamRunner.py
  • PyFoamSamplePlot.py

And then plot the necessary data using PyFoam

Show slide : PyFoamRunner.py PyFoamRunner.py can be used to run cases.


It also generates log files for later use.

Show slide : PyFoamSamplePlot.py This utility is used to plot the various data obtained from the previously set up sampleDict.
Show slide : Problem definition


Diagram

Shock Tube is an instrument -
  • used to replicate and direct blast waves at a sensor
  • to model actual explosion and their effects

In this case, the rectangular tube has low pressure on the right side and high pressure on the left side.


Both the pressures zones are separated by a thin diaphragm.

Type run/tutorials/compressible/rhoCentralFoam Open the Terminal and type the path for rhoCentralFoam inside compressible solver.
Type ls Type ls.

You can see the shockTube case.

Type cd shockTube Type cd shockTube
Point to the 3 files You can see three folders 0.org , constant and system.
On Terminal type

cp -r 0.org 0

We need to copy the 0 file from 0.org


So type cp -r 0.org 0

Type cd system Now, go to the system folder by typing

cd system

Type

gedit sampleDict

Open the sampleDict file using gedit.
In sampleDict file, do as narrated


Go to the bottom of the file and Remove U.Component(0).


Replace it with Ux Uy and Uz.


Remove rho as well.

Save the file and exit Save and exit the file.
Type cd .. Go one level back by typing cd ..
Type blockMesh Run the command blockMesh to mesh the geometry.
Type setFields After this type setFields to set the pressure boundary condition.
Type

pyFoamRunner.py rhoCentralFoam

Now we will use the pyFoam utility of pyFoamRunner.py


Type pyFoamRunner.py <followed by name of the solver > i.e. RhoCentralFoam.


This runs the case and creates a postProcessing log.

Switch to the terminal and type ls Go back to the terminal and type ls.


We can see the log files which are generated.

Type sample Now type sample to run the sample utility.
Type

pyFoamSamplePlot.py ./ --dir=postProcessing/sets –info

After this we can plot for various time steps using-

pyFoamSamplePlot.py ./ --dir=postProcessing/sets –info


This will show which fields we have with us.

Type pyFoamSamplePlot.py ./ --dir=postProcessing/sets --field=T --mode=timesInOne | gnuplot Then type pyFoamSamplePlot.py ./ --dir=postProcessing/sets --field=T --mode=timesInOne | gnuplot
The output generated will be a png file.
Type ls


Highlight/point to the png file

Type ls.


We can see the png file which is generated.

Show slide : Summary In this tutorial, we learnt about PyFoam Utilities.


We also learnt to-

  1. Check for various pyFoam utilities
  2. pyFoamRunner.py to run the solver
  3. pyFoamSamplePlot utility to generate a png file
Show Slide


Forum to answer questions

Please post your timed queries in this forum.
Show Slide


Forum to answer questions

Please post your general queries on OpenFOAM in this forum.
Show Slide


Textbook Companion

The FOSSEE team coordinates the TBC project.
Show Slide

Acknowledgement


The Spoken Tutorial Project is funded by NMEICT, MHRD, Govt. of India


For more details , visit this website.

Thank You This is Rahul Joshi from IIT Bombay signing off. Thanks for watching

Contributors and Content Editors

Nancyvarkey, Viraj20feb