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Tutorial: Turbulent flow in a lid driven cavity

Script : Chaitanya Talnikar, Shekhar Mishra , Rahul Joshi

Narration : Rahul Joshi

Keywords: Video tutorial ,CFD,Turbulent Flow in Lid driven cavity,OpenFOAM.

Visual Cue
Slide 1: Hello and welcome to the spoken tutorial on modelling Turbulent flow in a Lid Driven Cavity using OpenFOAM
Slide 2:

Learning Objectives

In this tutorial I will show you
  • Solving turbulent case in OpenFOAM and
  • Plotting streamlines in ParaView
Slide 3:

System Requirement

To record this tutorial I am using
  • Linux operating system Ubuntu version 12.04
  • OpenFoam version 2.1.1 and
  • ParaView version 3.12.0
Slide 4:

System Requirement

  • The tutorials were recorded using the versions specified in previous slide
  • Subsequently the tutorials were edited to latest versions
  • To install latest system requirements go to Installation Sheet
Slide 5 :


To practice this tutorial you should have some basic knowledge of
  • Turbulence modelling
  • Knowledge of how to solve flow in a Lid driven cavity
  • If not so please refer to the relevant tutorial on our website

Set up working Directory

This problem is identical in geometry and boundary condition to the 'Lid Driven Cavity' problem discussed in the basic level tutorial

Please make a note this problem is already set up in pisoFoam solver in OpenFoam directory

The boundary conditions are the Lid velocity U is 1 m/s

And we are solving this for a Reynolds number Re equal to 10000

Slide 6: Solver We are using a Transient solver for incompressible turbulent flow of Newtonian fluids called as pisoFoam
Steps in setting up the problem Now let us open the Terminal window by pressing Ctrl+Atl+T keys together
In the terminal window

Type cd tutorials

In the terminal window type run and press Enter

Now type cd space tutorials and press Enter

Type cd incompressible Now type cd space incompressible and press Enter
Type cd pisoFoam Now type cd space pisoFoam (Note that F here is capital ) and press Enter
Type ls

Two Folders les and ras

Cavity folder inside RAS

Now type ls and press Enter

In this you will see two folders les and ras

Our problem setup is inside ras folder which is called as reynolds averaged stress

Type cd ras


Our folder name is cavity

Now type cd space ras and press Enter

Now type ls and press Enter

Type cd cavity


You can see the cavity folder. Let me clear this off

Now type cd space cavity and press Enter

Now type ls and press Enter

Point to the 3 folders

Boundary and Initial conditions

0 folder

You can see three folders 0, constant and system

The initial conditions are specified within the files in the '0' directory

Now let us take a look at the files in the '0' directory

Inside the 0 folder

Type ls

To do this, in the command terminal type cd space 0 and press Enter

Now type ls and press Enter

Point to the files as per narration You can see the files named as epsilon, k, nut, nutilda, p, R and U

These files are to be kept as default until the inlet parameters don't change

If any changes are to be done please refer to the tutorial on Simulating flow in a channel using OpenFoam, to calculate these values

Type cd.. Now type cd space dot dot and press Enter

Let me clear this off

Type cd constant

Type ls

Let us open the constant folder

To do this type cd space constant and press Enter

Now type ls and press Enter

PolyMesh folder and fluid property files In this you will see the polyMesh folder containing
  • the geometry of the case inside blockMeshDict
  • and the fluid properties
Point to the two files as per narration In this case you will see two more files other than transportProperties named as RASProperties and turbulenceProperties

Let us open these two files

RASProperties In the terminal type gedit (space) RASProperties and press Enter

Scroll down

RASProperties contain the Reynolds average stress model for this case, which is kept as kEpsilon

Close this

turbulentProperties Now in the command terminal, type gedit space turbulentproperties and press Enter

Scroll down

The simulation type model for this case is kept as RASModel

Close this


Change the value of viscosity

Now let us open the transportProperties model

To do this, in the terminal type gedit space transportProperties and press Enter

The transportModel we are using here is Newtonian and the Viscosity is kept as 1 e raise to -4

Close this

Do not change the blockMeshDict file

The system folder is to be kept default

We are not changing the geometry in this case

So we need not go inside the polyMesh folder and look at the blockMeshDict file

It can be kept as it is

Type cd.. In the terminal type cd space dot dot and press Enter

We will keep the system folder default as there are no changes inside it

Meshing the geometry


Meshing is done

Now, we are done with the setup

We can mesh the geometry

To do this in the terminal window type blockMesh and press Enter

Meshing has been done

Running the solver : pisoFoam Now we can run the solver

To do this in the terminal type pisoFoam and press Enter

The iterations running can be seen in the terminal window

It may take some time for the iterations to stop

Post-processing the results in paraview The iterations running will stop at the end of the time step

To visualize the results let us open the ParaView window

To do this in the terminal type paraFoam and press Enter

This will open the ParaView window

View the geometry

Lid driven cavity geometry

Change the drop down menu from solid color to U

On the left hand side in the Object Inspector menu click on Apply

You can see the lid driven cavity geometry

A common visualization is surface plots

Change the display to Surface in the column.

And from the drop down menu change from solid colour to capital U

You can see the initial condition of velocity

Click on the Play button on VCR control for animation

Toggle on the color legend

Now on the top of the ParaView window you can see the VCR control

Click on the Play button

You can see the motion of the fluid inside the cavity

You can also toggle on the colour legend from the left hand side top of ParaView active variable control menu

Click on it. You can see the colour legend

Visualise the streamlines

Filters > Common > Stream Tracers

Now to visualise the stream lines
  • On top of the menu bar of ParaView
  • Go to Filters > Common and Stream Tracer
  • Click on it
Streamlines on top On the left hand side of the Object inspector menu you can see Apply. Click on it

You can see the stream lines at the centre of the lid driven cavity

Streamlines view You can also change the orientation in which the stream lines are viewed

To do this , scroll down

You can see the seed type

Shift to right >> change point source to line source Let me shift this to the right and change from point source to line source
Plot streamlines about X, Y and Z axis

Click on the Y axis

Click on the X axis

Delete this

You can see the X, Y and Z axes which are visible

Select any of these axis in which you would like to view the stream lines

I will select the Y axis and click Apply

You can see the streamlines along the Y axis

Similarly you can select the X axis and plot the streamlines along the X axis

Now delete this

Plot data over line

Save as .csv format

You can also plot the velocity along X and Y axis using plot over line

To do this go to Filters > Data Analysis and Plot over line

Save the data as dot csv from the File menu

Click on Save Data

Plot the results

Validate the results with Ghia

For Re= 10000

You can plot this data in LibreOffice spreadsheet or any other plotting software of your choice

Now let me switch back to the slides

The results obtained can be validated by using results of Ghia for Reynolds Number, Re equal to 10000

Slide 7:


That's all we have in this tutorial

Let us summarise.

  • Turbulent Flow in a Lid Driven Cavity
  • and plotting stream lines in ParaView

This brings us to the end of the tutorial

Slide 8: Assignment As an assignment
  • Modify the grid size of the cavity
  • Change it to 100 100 1
  • And visualise the results in ParaView using streamlines
  • Watch the video available at this URL:

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Slide 9:

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Slide 12:

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Slide 13: Acknowledgements Spoken Tutorials project is a part of the Talk to a Teacher project

It is supported by the National Mission on Education through ICT, MHRD, Government of India

More information on the this mission is available at this URL

About the contributor The script is contributed by Shekhar Mishra and Chaitanya talnikar

This is Rahul Joshi from IIT BOMBAY signing off.

Thanks for joining

Contributors and Content Editors

DeepaVedartham, Nancyvarkey, Pravin1389, Rahuljoshi