Difference between revisions of "OpenFOAM/C2/Basic-Post-Processing-using-ParaView/English"

1. Variable visualization
2. Velocity vector visualization
3. Streamlines visualization
4. Slice and Clip filters

System Requirement

• Ubuntu Linux Operating system 16.04 LTS
• OpenFOAM version 4.1
• ParaView version 5.0

Pre-requisite

• Basic knowledge of Linux terminal commands
• Experience with simulating cases in OpenFOAM
• Working skills in ParaView

If not, please go through the previous OpenFOAM spoken tutorials on this website: https://spoken-tutorial.org/

• OpenFOAM has provided an inbuilt case file for pitzDaily.

• focus on post-processing of the pitzDaily solution
• learn to visualize flow field variables like velocity, pressure, vorticity, etc.
• learn to visualize velocity vector within the flow field

I have already copied this file in my work folder and run the simulation in my machine using simpleFoam.

cd /opt/openfoam4/tutorials/incompressible/simpleFoam/pitzDaily

You will see all these files here.

This will open the ParaView window.

This is on the top left corner of the Properties panel.

You will see the different types of Volume Fields available for visualization.

Here we will visualize the velocity field within the domain.

Please note that the U variable is available to visualization, by default.

This will show the initial flow conditions on the Graphic window.

This will visualize the flow velocity field after 298 iterations.

Thus we have learnt to visualize field variables in ParaView.

To do this, click on the Glyph filter on the toolbar.

This will add a new component to the Pipeline window.

• Glyph type is arrow
• Scale Mode is off
• Scaling Factor is 0.003

Keep the rest as default.

You will see small velocity vectors visualized within the domain.

Thus we have learned to create velocity vector in a flow field.

Now let us go back to the next problem statement.

OpenFOAM has provided an inbuilt case file for flow over a motorBike.

• focus on post-processing of the motorBike solution
• learn to create stream lines and view them in ParaView

I have already copied this file in my work folder.

Then run the simulation using simpleFoam.

Here I will type cd ..

cd motorBike

To see the content inside type ls

You will see all these files here.

Now to post-process this simulation, type paraFoam in the command terminal.

This will open the ParaView window.

To include the last iteration, click on the lastFrame button on the Menu bar.

Go to the Tool Bar and set the directional view to +Y.

Change the vtkBlockColors to U from the drop down options.

Now scroll down on the Properties panel to Opacity.

Reduce the Opacity to make the domain transparent like this.

You will be able to see the motor bike with the rider through the domain now.

To create streamlines around the motor bike click on stream Tracer filter on the Tool Bar.

This will add a new component within the Pipeline browser.

Here in the Properties panel change the Point to (5 0 1) coordinates within Seeds section.

This will change the location of the center of the stream lines.

Now change the Number of Points to 15.

This show the number of stream lines you want to create.

Change the Radius to 1.

This changes the radius of the stream line points.

Keep the rest of the values as default.

After all changes have been made, click Apply on the Properties menu of the stream Tracer.

You can see stream lines around the motor bike along with their magnitude.

Thus we have learned to create stream lines in ParaView.

After this close the ParaView window.

We will go to the next problem statement.

• focus on post-processing of the hotRadiationRoom solution
• learn to use filters like clip and slice in ParaView

Go to the hotRadiationRoom tutorial in BuoyantSimpleFoam within heatTransfer case directory.

You can find this within OpenFOAM-4.1>tutorials directory.

I have already copied this file in my work folder and run the simulation using BuoyantSimpleFoam.

Now open this solved case file in the command terminal.

Here I will type cd /opt/openfoam4/tutorials/heatTransfer/buoyantSimpleFoam/hotRadiationRoom

To see the content inside type ls.

You will see all these files here.

Now to post-process this simulation, type paraFoam, in the command terminal.

This will open the ParaView window.

This will show the domain geometry on the Graphic window.

Now if you scroll down within the Properties menu.

You will see the different types of Volume Field available for visualization.

Here we will visualize the Temperature field within the domain.

For this check the T variable within the Volume Field and click on Apply.

Now go to the Tool Bar.

Change the vtkBlockColors to T from the drop down options.

This will show the initial flow conditions on the Graphic window.

Go to the Tool Bar and set the directional view to +Z.

Now go to the Menu bar and click Play button.

You can see the temperature field pattern of the converged solution.

This will visualize the flow temperature field after 900 iterations.

Now click and scroll on the Graphic window.

You can clearly see the temperature gradient due to radiation near the hot object.

But we are unable to visualize the whole section.

Thus we need to get a sectional or planar view of the field.

To do this, click on the clip filter on the Tool Bar.

This will add a new component to the Pipeline window.

Now in the Properties panel select Y Normal.

Scroll on the Graphic window like this. Then shift the reference section to the middle of the hot box.

After this click Apply on the Properties panel.

Now change the view direction to +Y on the toolbar.

Thus you can see the sectional view of the temperature field

Now delete this filter to visualize the full domain from the Properties panel.

To do this, click on the slice filter on the toolbar.

This will add a new component to the Pipeline window.

Now in the Properties panel select Y Normal.

Scroll on the Graphic window like this.

Now change the view direction to +Z on the toolbar.

Then shift the reference section to the middle of the hot box.

After this click Apply on the Properties panel.

Now change the view direction to +Y on the toolbar.

Thus you can see a plane section view of the temperature field.

In this tutorial, we learnt some basic Post-Processing using ParaView.

• Visualize field variable
• Create Velocity Vectors
• Create Stream lines
• Use clip and slice filters

This will help you understand the post-processing using ParaView better.

Forum to answer questions

Forum to answer questions

Case Study Project

Lab Migration Project

Acknowledgement

https://spoken-tutorial.org

For more details, visit this website.