Difference between revisions of "OpenFOAM/C3/Turbulent-Flow-in-a-Lid-driven-Cavity/English"

From Script | Spoken-Tutorial
Jump to: navigation, search
Line 72: Line 72:
  
  
If not so please refer to the revelent tutorial on our website
+
If not so please refer to the revelent '''tutorial''' on our website
  
  
Line 84: Line 84:
  
  
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| This problem is identical in geometry and boundary
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| This problem is identical in '''geometry and boundary'''
  
  
conditions to the 'Lid Driven Cavity' problem discussed in the  
+
'''conditions''' to the ''''Lid Driven Cavity'''' problem discussed in the  
  
  
Line 93: Line 93:
  
  
Please make a note this problem is already set up in
+
Please make a note this '''problem''' is already set up in
  
  
'''pisoFoam '''solver in OpenFoam directory.
+
'''pisoFoam solver''' in OpenFoam directory.
  
  
The boundary conditions are Lid velocity , '''U =1m/s'''
+
The '''boundary conditions''' are Lid velocity , '''U =1m/s'''
  
  
And we are solving this for a Reynolds number '''Re =10000'''
+
And we are solving this for a '''Reynolds number''' '''Re =10000'''
  
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 5: Solver  
 
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 5: Solver  
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| We will be using the Transient solver for incompressible,  
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| We will be using the '''Transient''' '''solver''' for '''incompressible''',  
  
  
turbulent flow of Newtonian fluids.  
+
'''turbulent flow of Newtonian fluids'''.  
  
  
It is called pisoFoam
+
It is called '''pisoFoam'''
  
  
Line 119: Line 119:
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Steps in setting up the problem
 
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Steps in setting up the problem
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Now let me open the terminal window
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Now let me open the '''terminal window'''
  
  
To do this press Ctrl+Atl+t keys simultaneously on your keyboard.
+
To do this press '''Ctrl+Atl+t keys''' simultaneously on your '''keyboard'''.
  
  
Line 132: Line 132:
  
 
Go to the pisoFoam folder
 
Go to the pisoFoam folder
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| In the terminal window type run and press enter
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| In the terminal window '''type run''' and press enter
  
  
Line 148: Line 148:
  
 
Cavity folder inside RAS
 
Cavity folder inside RAS
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Now type ls and press enter
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Now type''' ls''' and press enter
  
  
In this you will see two folders les and ras
+
In this you will see two folders '''les and ras'''
  
  
Line 167: Line 167:
  
  
Now type ls and press enter
+
Now type''' ls''' and press enter
  
  
You can see the cavity folder
+
You can see the '''cavity''' folder
  
  
Line 176: Line 176:
  
  
Now type ls and press enter
+
Now type''' ls''' and press enter
  
 
|-
 
|-
Line 186: Line 186:
  
  
The initial conditions are specified within the files in the ''''0'''' directory.
+
The '''initial conditions''' are specified within the files in the ''''0'''' directory.
  
  
Line 210: Line 210:
  
  
Now type ls and press enter
+
Now type '''ls''' and press enter
  
  
Line 216: Line 216:
  
  
These files are to be kept as default until the inlet parameters don't change.
+
These files are to be kept as default until the '''inlet''' parameters don't change.
  
  
Line 232: Line 232:
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Let us view the constant folder
 
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Let us view the constant folder
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Now type cd .. and press enter
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Now type '''cd ..''' and press enter
  
  
Line 238: Line 238:
  
  
Let us open the constant folder.
+
Let us open the '''constant''' folder.
  
  
Line 254: Line 254:
  
  
And the fluid properties.
+
And the '''fluid properties'''.
  
  
Line 260: Line 260:
  
  
Let us open these two files
+
Let us open these two '''files'''
  
 
|-
 
|-
Line 267: Line 267:
  
  
RASProperties contain the Reynolds average stress model for the case.
+
'''RASProperties''' contain the '''Reynolds average stress model''' for the case.
  
  
Line 283: Line 283:
  
  
turbulentProperties contain the turbulent model ,
+
'''turbulentProperties''' contain the '''turbulent model''' ,
  
  
Line 293: Line 293:
  
 
Change the value of viscosity
 
Change the value of viscosity
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| In the terminal window type cd ..
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| In the terminal window type '''cd ..'''
  
 
and press enter.
 
and press enter.
Line 314: Line 314:
  
  
So we need not go inside the polyMesh
+
So we need not go inside the '''polyMesh'''
  
  
Line 323: Line 323:
  
  
In the terminal type cd .. and press enter
+
In the terminal type '''cd ..''' and press enter
  
  
We will keep the system folder default
+
We will keep the '''system''' folder default
  
  
Line 342: Line 342:
  
  
Now we can mesh the geometry
+
Now we can '''mesh''' the geometry
  
  
Line 348: Line 348:
  
  
Meshing has been done
+
'''Meshing '''has been done
  
 
|-
 
|-
Line 358: Line 358:
  
  
the iterations running can be seen in the terminal window.
+
the '''iterations''' running can be seen in the terminal window.
  
  
Line 368: Line 368:
  
  
To visualize the results let us open the paraview window.
+
To visualize the results let us open the '''paraview''' window.
  
  
To do this in the terminal type paraFoam and press enter.
+
To do this in the terminal '''type paraFoam''' and press enter.
  
  
This will open the paraview window
+
This will open the '''paraview''' window
  
 
|-
 
|-
Line 393: Line 393:
  
  
Change the display to Surface in the column and  
+
Change the display to '''Surface''' in the column and  
  
  
Line 406: Line 406:
  
  
Click the play button  
+
Click the '''play''' button  
  
  
Line 415: Line 415:
  
  
of paraview active variable control menu.
+
of '''paraview''' '''active variable control menu'''.
  
  
Line 431: Line 431:
  
  
On the top menu bar of paraview
+
On the top menu bar of '''paraview'''
  
  
Line 441: Line 441:
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Streamlines on top of the  
 
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Streamlines on top of the  
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| On the left hand side in Object inspector menu click on Apply.
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| On the left hand side in '''Object inspector menu''' click on '''Apply'''.
  
  
You can see the stream lines near the top surface of moving wall.
+
You can see the '''stream lines''' at the center of the lid driven cavity.
  
  
Line 472: Line 472:
  
  
in which you would like to view the stream lines.
+
in which you would like to view the '''stream lines'''.
  
  
Line 478: Line 478:
  
  
You can see the streamlines along the Y axis.
+
You can see the '''streamlines''' along the Y axis.
  
  
Line 484: Line 484:
  
  
plot streamlines along the X axis
+
'''plot streamlines''' along the X axis
  
  
Line 500: Line 500:
 
Save the data as''' .(dot) csv''' file from file menu
 
Save the data as''' .(dot) csv''' file from file menu
  
Click on save data
+
Click on '''save data'''
  
 
|-
 
|-
Line 509: Line 509:
  
 
For Re= 10000
 
For Re= 10000
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| You can plot this data in '''libreoffice spreadsheet '''or any other plotting software of your choice
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| You can plot this data in '''libreoffice spreadsheet '''or any other '''plotting''' software of your choice
  
 
Let me switch back to the slides
 
Let me switch back to the slides
Line 523: Line 523:
 
Let us summarise
 
Let us summarise
  
In this tutorial we learnt Turbulent Flow in a Lid Driven Cavity
+
In this tutorial we learnt '''Turbulent Flow in a Lid Driven Cavity'''
  
And plotting streamlines in paraView
+
And '''plotting streamlines '''in''' paraView'''
  
 
This brings us to the end of the tutorial
 
This brings us to the end of the tutorial
Line 533: Line 533:
 
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| As an assignment
 
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| As an assignment
  
Modify the grid size of the cavity
+
Modify the '''grid size''' of the cavity
  
 
Change it to (100 100 1)
 
Change it to (100 100 1)
  
Visualise the results in paraview using streamlines
+
Visualise the results in paraview using '''streamlines'''
  
 
|-
 
|-

Revision as of 18:55, 28 February 2013

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
Narration
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 flow case in OpenFOAM


Plotting streamlines in Paraview



Slide 3:


System Requirement

To record this tutorial I am using Linux operating system Ubuntu 12.04


OpenFoam version 2.1.1


Paraview version 3.12.0



Slide 4 :


Prerequisites

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 revelent tutorial on our website



Demo:

Set up working Directory


This problem is identical in geometry and boundary


conditions 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 Lid velocity , U =1m/s


And we are solving this for a Reynolds number Re =10000

Slide 5: Solver We will be using the Transient solver for incompressible,


turbulent flow of Newtonian fluids.


It is called pisoFoam



Steps in setting up the problem Now let me open the terminal window


To do this press Ctrl+Atl+t keys simultaneously on your keyboard.



In the terminal window


Go to the pisoFoam folder

In the terminal window type run and press enter


Now type cd tutorials and press enter


type cd incompressible and press enter


type cd pisoFoam (Note that F here is capital ) and press enter

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



Cavity folder Our folder name is cavity.


Now type cd ras and press enter


Now type ls and press enter


You can see the cavity folder


type cd cavity and press enter


Now type ls and press enter

Boundary and Initial conditions


0 folder

In this you will see three folders 0,constant and system.


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


Let us take a look at the files in the '0' directory.

Inside the 0 folder


ls to view the files inside this folder


Do not edit the files unitil inlet parameters don't change


Refer to the earlier tutorial on channel flow for calculating these values


Type the following command

cd 0 and press enter


Now type ls and press enter


You can see 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.



Let us view the constant folder Now type cd .. and press enter


Let me clear this off


Let us open the constant folder.


To do this type cd constant 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.


In this you will see two more files named RASProperties and turbulenceProperties


Let us open these two files

RASProperties In the terminal type gedit RASProperties and press enter.


RASProperties contain the Reynolds average stress model for the case.


Which is kept as kepsilon


close this

turbulentProperties in the terminal now type gedit turbulentproperties and press enter


Scroll down


turbulentProperties contain the turbulent model ,


Simulation type for this case is kept as RASModel

TransportModel


Change the value of viscosity

In the terminal window type cd ..

and press enter.


The transportModel we are using here is Newtonian


Viscosity is kept as 1 e raise to -4


close this file

Do ot 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


and look at the blockMeshDict file


It can be kept as it is


In the terminal type cd .. and press enter


We will keep the system folder default


As there are no changes inside it

Meshing the geometry


blockMesh


Meshing is done

We are done with the setup


Now we can mesh the geometry


To do this in the teminal 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 till the iterations stop.

Post-processing the results in paraview Iterations 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 visualisation is surface plots.


Change the display to Surface in the column and


from the drop down menu change from solid color to U

Click on the Play button on VCR control for animation


Toggle on the color legend

On top of the paraview window you can see the VCR control


Click the play button


You can see the motion of the fluid inside the cavity.


Also toggle on the color legend on the left hand side top


of paraview active variable control menu.


Click on it

Visualise the streamlines


Filters > Common > Stream Tracers


To visualise the stream lines


On the top menu bar of paraview


Go to Filters > Common > Stream Tracers


Click on it

Streamlines on top of the On the left hand side in Object inspector menu click on Apply.


You can see the stream lines at the center of the lid driven cavity.


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


To do this scroll down


You can see the seed type


Let me shift this to the right


and change the seed type from point source to line source

Plot streamlines about X, Y and Z axis


Click on the Y axis


X, Y and Z axis are visible select any one of these axis


in which you would like to view the stream lines.


Click on the Y axis


You can see the streamlines along the Y axis.


Similarly you can select the X axis and


plot streamlines along the X axis


Now delete this

Plot data over line


Save as .csv format

You can also plot the velocity along the x and y axis using plot over line

To do this go to Filter > Data Analysis > Plot over line

Save the data as .(dot) csv file from file menu

Click on save data

Plot the results


Validate the results with Ghia et.al.

For Re= 10000

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

Let me switch back to the slides

The results obtained can be validated by results obtained by Ghia et.al for Reynolds No , Re= 10000

Slide :

Summary

Thats all we have in this tutorial

Let us summarise

In this tutorial we learnt Turbulent Flow in a Lid Driven Cavity

And plotting streamlines in paraView

This brings us to the end of the tutorial

Slide : Assignment As an assignment

Modify the grid size of the cavity

Change it to (100 100 1)

Visualise the results in paraview using streamlines

The video available at this URL:

http://spoken-tutorial.org/What_is_a_Spoken_Tutorial

It summarizes the Spoken Tutorial project.

If you do not have good bandwidth, you can download and watch it.

The Spoken Tutorial Project Team

-Conducts workshops using spoken tutorials

-Gives certificates to those who pass an online test

-For more details, please write to us at

contacts@spoken-tutorial.org

Spoken Tutorials are part of Talk to a Teacher project,

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

This project is coordinated by http://spoken-tutorial.org

More information on the same is available at the following URL link http://spoken-tutorial.org/NMEICT-Intro

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