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

From Script | Spoken-Tutorial
Jump to: navigation, search
Line 66: Line 66:
  
  
Turbulence modelling
+
'''Turbulence modelling'''
  
  
Knowledge of how to solve flow in a Lid driven cavity
+
Knowledge of how to solve flow in a '''Lid driven cavity'''
  
  
Line 93: Line 93:
  
  
Please make a note this problem is already set up in pisoFoam solver in OpenFoam directory.
+
Please make a note this problem is already set up in
  
  
The boundary conditions are Lid velocity , U =1m/s
+
'''pisoFoam '''solver in OpenFoam directory.
  
  
And we are solving this for a Reynolds number Re =10000
+
The boundary conditions are Lid velocity , '''U =1m/s'''
 +
 
 +
 
 +
And we are solving this for a Reynolds number '''Re =10000'''
  
 
|-
 
|-
Line 132: Line 135:
  
  
Now type cd tutorials and press enter
+
Now type '''cd tutorials''' and press enter
  
  
type cd incompressible and press enter
+
type '''cd incompressible''' and press enter
  
  
type cd pisoFoam (Note that F here is capital ) and press enter
+
type '''cd pisoFoam''' (Note that F here is capital ) and press enter
  
 
|-
 
|-
Line 151: Line 154:
  
  
Our problem is setup inside ras folder which is called as reynolds averaged stress  
+
Our problem is setup inside '''ras''' folder which is called as '''reynolds averaged stress'''
  
  
Line 158: Line 161:
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Cavity folder
 
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Cavity 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;"| Our folder name is cavity.
+
| 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;"| Our folder name is '''cavity'''.
  
  
Now type cd ras and press enter
+
Now type '''cd ras''' and press enter
  
  
Line 170: Line 173:
  
  
type cd cavity and press enter
+
type '''cd cavity''' and press enter
  
  
Line 180: Line 183:
  
 
0 folder
 
0 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 this you will see three folders 0,constant and system.
+
| 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 this you will see three folders''' 0,constant and system'''.
  
  
The initial conditions are specified within the files in the '0' directory.
+
The initial conditions are specified within the files in the ''''0'''' directory.
  
  
Let us take a look at the files in the '0' directory.  
+
Let us take a look at the files in the ''''0'''' directory.  
  
 
|-
 
|-
Line 204: Line 207:
 
| 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;"| Type the following command
 
| 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;"| Type the following command
  
cd 0 and press enter
+
'''cd 0''' and press enter
  
  
Line 210: Line 213:
  
  
You can see files named as epsilon, k, nut, nutilda,p,R and U.
+
You can see files named as '''epsilon, k, nut, nutilda,p,R and U'''.
  
  
Line 219: Line 222:
  
  
On Simulating flow in a channel using OpenFoam  
+
On '''Simulating flow in a channel''' using OpenFoam  
  
  
Line 238: Line 241:
  
  
To do this type cd constant and press enter
+
To do this type '''cd constant''' and press enter
  
 
|-
 
|-
Line 245: Line 248:
  
  
| 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 this you will see the polyMesh folder containing the geometry  
+
| 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 this you will see the '''polyMesh''' folder containing the geometry  
  
  
of the case inside blockMeshDict
+
of the case inside '''blockMeshDict'''
  
  
Line 254: Line 257:
  
  
In this you will see two more files named RASProperties and turbulenceProperties
+
In this you will see two more files named '''RASProperties''' and''' turbulenceProperties'''
  
  
Line 261: Line 264:
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| RASProperties
 
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| RASProperties
| 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 type gedit RASProperties 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 type''' gedit RASProperties''' and press enter.
  
  
Line 267: Line 270:
  
  
Which is kept as kepsilon
+
Which is kept as '''kepsilon'''
  
  
Line 274: Line 277:
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| turbulentProperties
 
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| turbulentProperties
| 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 now type gedit turbulentproperties 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 now type '''gedit turbulentproperties''' and press enter
  
  
Line 283: Line 286:
  
  
Simulation type for this case is kept as RASModel
+
Simulation type for this case is kept as '''RASModel'''
  
 
|-
 
|-
Line 295: Line 298:
  
  
The transportModel we are using here is Newtonian
+
The '''transportModel '''we are using here is '''Newtonian'''
  
  
Viscosity is kept as 1 e raise to -4
+
Viscosity is kept as '''1 e raise to -4'''
  
  
Line 314: Line 317:
  
  
and look at the blockMeshDict file
+
and look at the '''blockMeshDict''' file
  
  
Line 342: Line 345:
  
  
To do this in the teminal window type blockMesh and press Enter
+
To do this in the teminal window '''type blockMesh''' and press Enter
  
  
Line 352: Line 355:
  
  
To do this in the terminal type 'pisoFoam' and press enter
+
To do this in the terminal type '''pisoFoam''' and press enter
  
  
Line 362: Line 365:
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Post-processing the results in paraview
 
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Post-processing the results in paraview
| 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;"| Iterations will stop at the end of the time step.
+
| 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;"| '''Iterations''' will stop at the end of the time step.
  
  
Line 381: Line 384:
  
 
Change the drop down menu from solid color to U
 
Change the drop down menu from solid color to U
| 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 the 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 the '''Object Inspector menu''' click on '''Apply'''
  
  
You can see the lid driven cavity geometry.
+
You can see the '''lid driven cavity''' geometry.
  
  
A common visualisation is surface plots.  
+
A common visualisation is '''surface plots'''.  
  
  
Line 393: Line 396:
  
  
from the drop down menu change from solid color to U
+
from the drop down menu change from '''solid color to U'''
  
 
|-
 
|-
Line 400: Line 403:
  
 
Toggle on the color legend  
 
Toggle on the color legend  
| 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 top of the paraview window you can see the VCR control
+
| 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 top of the paraview window you can see the '''VCR control'''
  
  
Line 409: Line 412:
  
  
Also toggle on the color legend on the left hand side top  
+
Also '''toggle on''' the '''color legend''' on the left hand side top  
  
  
Line 425: Line 428:
  
  
| 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;"| To visualise the stream lines
+
| 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;"| To visualise the '''stream lines'''
  
  
Line 431: Line 434:
  
  
Go to Filters > Common > Stream Tracers
+
Go to '''Filters > Common > Stream Tracer'''s
  
  
Line 444: Line 447:
  
  
You can also change the orientation in which the stream lines are viewed.
+
You can also change the '''orientation''' in which the stream lines are viewed.
  
  
Line 450: Line 453:
  
  
You can see the seed type
+
You can see the''' seed type'''
  
  
Line 456: Line 459:
  
  
and change the seed type from point source to line source
+
and change the seed type from''' point source to line source'''
  
 
|-
 
|-
Line 493: Line 496:
 
| 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 also plot the velocity along the x and y axis using plot over line
 
| 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 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
+
To do this go to '''Filter > Data Analysis > Plot over line'''
  
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 506: 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
  
The results obtained can be validated by results obtained by Ghia et.al for Reynolds No , Re= 10000
+
The results obtained can be '''validated''' by results obtained by '''Ghia et.al for Reynolds No , Re= 10000'''
  
 
|-
 
|-

Revision as of 10:47, 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 near the top surface of moving wall.


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