Difference between revisions of "OpenFOAM/C3/Turbulent-Flow-in-a-Lid-driven-Cavity/English-timed"
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| 00:01 | | 00:01 | ||
| − | | Hello and welcome to the spoken tutorial on modelling '''Turbulent flow in a Lid Driven Cavity using OpenFOAM''' | + | | Hello and welcome to the spoken tutorial on modelling '''Turbulent flow in a Lid Driven Cavity''' using '''OpenFOAM'''. |
|- | |- | ||
| 00:09 | | 00:09 | ||
| − | | In this tutorial I will show you Solving '''turbulent''' case in '''OpenFOAM''' | + | | In this tutorial, I will show you: |
| − | Plotting '''streamlines''' in '''Paraview''' | + | * Solving '''turbulent''' case in '''OpenFOAM''' |
| + | * Plotting '''streamlines''' in '''Paraview'''. | ||
|- | |- | ||
| 00:20 | | 00:20 | ||
| − | | To record this tutorial I am using '''Linux operating system''' | + | | To record this tutorial, I am using: |
| − | ''' | + | * '''Linux operating system Ubuntu''' version 12.04 |
| − | ''' | + | * '''OpenFoam''' version 2.1.1 |
| + | * '''Paraview''' version 3.12.0 | ||
|- | |- | ||
| 00:33 | | 00:33 | ||
| − | | To practice this tutorial you should have some basic knowledge of '''Turbulence modelling''' | + | | To practice this tutorial, you should have some basic knowledge of '''Turbulence modelling''', knowledge of how to solve flow in a '''Lid driven cavity'''. |
|- | |- | ||
| 00:43 | | 00:43 | ||
| − | |If not so please refer to the | + | |If not so, please refer to the relevant tutorial on our website. |
|- | |- | ||
| 00:50 | | 00:50 | ||
| − | | This problem is identical in '''geometry | + | | This problem is identical in '''geometry''' and '''boundary conditions''' to the ''''Lid Driven Cavity'''' problem discussed in the basic level tutorial. |
|- | |- | ||
| 00:59 | | 00:59 | ||
| − | |Please make a note this | + | |Please make a note this problem is already set up in''''pisoFoam' solver''' in OpenFoam directory. |
|- | |- | ||
| 01:07 | | 01:07 | ||
| − | |The '''boundary conditions''' are | + | |The '''boundary conditions''' are the '''Lid velocity U =1 m/s'''. We are solving this for a '''Reynolds number Re =10000'''. |
|- | |- | ||
| 01:20 | | 01:20 | ||
| − | | We are using | + | | We are using a transient solver for '''in-compressible, turbulent flow''' of '''Newtonian fluid'''s called as '''pisoFoam'''. |
|- | |- | ||
| 01:29 | | 01:29 | ||
| − | | Now let us open the '''terminal window''' by pressing '''Ctrl+Atl+t keys''' together. | + | | Now, let us open the '''terminal window''' by pressing '''Ctrl+Atl+t keys''' together. |
|- | |- | ||
| 01:37 | | 01:37 | ||
| − | | In the terminal window ''' | + | | In the terminal window, type "run" and press '''Enter'''. Now type '''cd space tutorials''' and press '''Enter'''. Now type '''cd incompressible''' and press '''Enter'''. |
|- | |- | ||
| 01:59 | | 01:59 | ||
| − | |Now | + | |Now, type '''cd pisoFoam''' (Note that F here is capital ) and press '''Enter'''. |
|- | |- | ||
| 02:10 | | 02:10 | ||
| − | |Now type''' | + | |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''' | + | Our problem setup is inside '''ras''' folder which is called as '''reynolds averaged stress'''. |
|- | |- | ||
| 02:26 | | 02:26 | ||
| − | | Our folder name is '''cavity'''.Now type '''cd ras''' and press | + | | Our folder name is '''cavity'''. Now type '''cd ras''' and press '''Enter'''. Now type''' ls''' and press '''Enter'''. |
|- | |- | ||
| 02:39 | | 02:39 | ||
| − | |You can see the '''cavity''' folder | + | |You can see the '''cavity''' folder. Let me clear this off. Now type '''cd cavity''' and press '''Enter'''. Now type "ls" and press '''Enter'''. |
|- | |- | ||
| 02:57 | | 02:57 | ||
| − | | You can see three folders''' 0,constant and system'''.The '''initial conditions''' are specified within the files in the | + | | You can see three folders''' 0, constant''' and '''system'''. The '''initial conditions''' are specified within the files in the '0' directory. |
|- | |- | ||
| 03:08 | | 03:08 | ||
| − | |Let us take a look at the files in the | + | |Let us take a look at the files in the '0' directory. |
|- | |- | ||
|03:12 | |03:12 | ||
| − | |To do this in the command terminal type cd 0 and press | + | |To do this, in the command terminal, type '''cd 0''' and press '''Enter'''. Now type "ls" and press '''Enter'''. |
|- | |- | ||
|03:22 | |03:22 | ||
| − | |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'''. |
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| Line 89: | Line 91: | ||
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|03:41 | |03:41 | ||
| − | | | + | |on '''Simulating flow in a channel using OpenFoam''' to calculate these values. |
|- | |- | ||
|03:47 | |03:47 | ||
| − | |Now type cd .. and press | + | |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'''. Now type "ls" and press '''Enter'''. |
|- | |- | ||
| 04:08 | | 04:08 | ||
| − | | In this you will see the '''polyMesh''' folder containing the geometry of the case inside '''blockMeshDict''' | + | | In this, you will see the '''polyMesh''' folder containing the geometry of the case inside '''blockMeshDict''' and the '''fluid properties'''. |
|- | |- | ||
| 04:19 | | 04:19 | ||
| − | |In this case you will see two more files other than '''transportProperties''' named as '''RASProperties''' and''' turbulenceProperties''' | + | |In this case, you will see two more files other than '''transportProperties''' named as '''RASProperties''' and''' turbulenceProperties'''. |
|- | |- | ||
| 04:29 | | 04:29 | ||
| − | |Let us open these two | + | |Let us open these two files. |
|- | |- | ||
| 04:32 | | 04:32 | ||
| − | | In the terminal type''' gedit (space) RASProperties''' and press | + | | In the terminal, type''' gedit (space) RASProperties''' and press '''Enter'''. Let me drag this to the capture area. |
|- | |- | ||
| 04:49 | | 04:49 | ||
| − | |Scroll | + | |Scroll down. '''RASProperties''' contains the '''Reynolds average stress model''' for this case which is kept as '''kepsilon''' close this. |
|- | |- | ||
| 05:03 | | 05:03 | ||
| − | | Now in the command terminal now type'''gedit (space) turbulentproperties''' and press | + | | Now in the command terminal, now type '''gedit (space) turbulentproperties''' and press '''Enter'''. |
|- | |- | ||
| 05:15 | | 05:15 | ||
| − | | Scroll down '''Simulation type model''' for this case is kept as '''RASModel'''Close this | + | | Scroll down. '''Simulation type model''' for this case is kept as '''RASModel'''Close this. |
|- | |- | ||
| 05:25 | | 05:25 | ||
| − | | Now let us open the '''transportProperties''' model to this In the terminal window type '''gedit transportProperties '''and press | + | | Now let us open the '''transportProperties''' model. to this In the terminal window, type '''gedit transportProperties '''and press '''Enter'''. |
|- | |- | ||
Revision as of 12:29, 28 June 2016
| Time | Narration |
| 00:01 | Hello and welcome to the spoken tutorial on modelling Turbulent flow in a Lid Driven Cavity using OpenFOAM. |
| 00:09 | In this tutorial, I will show you:
|
| 00:20 | To record this tutorial, I am using:
|
| 00:33 | To practice this tutorial, you should have some basic knowledge of Turbulence modelling, knowledge of how to solve flow in a Lid driven cavity. |
| 00:43 | If not so, please refer to the relevant tutorial on our website. |
| 00:50 | This problem is identical in geometry and boundary conditions to the 'Lid Driven Cavity' problem discussed in the basic level tutorial. |
| 00:59 | Please make a note this problem is already set up in'pisoFoam' solver in OpenFoam directory. |
| 01:07 | The boundary conditions are the Lid velocity U =1 m/s. We are solving this for a Reynolds number Re =10000. |
| 01:20 | We are using a transient solver for in-compressible, turbulent flow of Newtonian fluids called as pisoFoam. |
| 01:29 | Now, let us open the terminal window by pressing Ctrl+Atl+t keys together. |
| 01:37 | In the terminal window, type "run" and press Enter. Now type cd space tutorials and press Enter. Now type cd incompressible and press Enter. |
| 01:59 | Now, type cd pisoFoam (Note that F here is capital ) and press Enter. |
| 02:10 | 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. |
| 02:26 | Our folder name is cavity. Now type cd ras and press Enter. Now type ls and press Enter. |
| 02:39 | You can see the cavity folder. Let me clear this off. Now type cd cavity and press Enter. Now type "ls" and press Enter. |
| 02:57 | You can see three folders 0, constant and system. The initial conditions are specified within the files in the '0' directory. |
| 03:08 | Let us take a look at the files in the '0' directory. |
| 03:12 | To do this, in the command terminal, type cd 0 and press Enter. Now type "ls" and press Enter. |
| 03:22 | You can see files named as epsilon, k, nut, nutilda, p, R and U. |
| 03:30 | 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 |
| 03:41 | on Simulating flow in a channel using OpenFoam to calculate these values. |
| 03:47 | 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. Now type "ls" and press Enter. |
| 04:08 | In this, you will see the polyMesh folder containing the geometry of the case inside blockMeshDict and the fluid properties. |
| 04:19 | In this case, you will see two more files other than transportProperties named as RASProperties and turbulenceProperties. |
| 04:29 | Let us open these two files. |
| 04:32 | In the terminal, type gedit (space) RASProperties and press Enter. Let me drag this to the capture area. |
| 04:49 | Scroll down. RASProperties contains the Reynolds average stress model for this case which is kept as kepsilon close this. |
| 05:03 | Now in the command terminal, now type gedit (space) turbulentproperties and press Enter. |
| 05:15 | Scroll down. Simulation type model for this case is kept as RASModelClose this. |
| 05:25 | Now let us open the transportProperties model. to this In the terminal window, type gedit transportProperties and press Enter. |
| 05:36 | The transportModel we are using here is Newtonian and Viscosity is kept as 1 e raise to -4close this |
| 05:46 | We are not changing the geometry in this case So we need not go inside the polyMesh folder and look at the blockMeshDict file |
| 05:54 | 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. |
| 06:08 | Now we are done with the setup we can mesh the geometryTo do this in the teminal window type blockMesh and press Enter Meshing has been done |
| 06:22 | Now we can run the solverTo do this in the terminal type pisoFoam and press enterthe iterations running can be seen in the terminal window. |
| 06:34 | It may take some time for the iterations to stop. |
| 06:40 | 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 |
| 06:57 | On the left hand side in the Object Inspector menu click on ApplyYou can see the lid driven cavity geometry.A common visualisation is surface plots. |
| 07:09 | Change the display to Surface in the column and from the drop down menu change from solid color to UYou can see the initial condition of velocity |
| 07:22 | Now on top of the paraview window you can see the VCR controlClick on the play button
You can see the motion of the fluid inside the cavity. |
| 07:34 | You can also toggle on the color legend from the left hand side top of paraview active variable control menu.Click on it. you can see colour legend |
| 07:46 | Now to visualise the stream linesOn the top menu bar of paraviewGo to Filters > Common > Stream Tracers Click on it |
| 07:58 | 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 center of the lid driven cavity. |
| 08:10 | You can also change the orientation in which the stream lines are viewed.To do this , scroll down
You can see the seed type |
| 08:21 | Let me shift this to the right change from point source to line source |
| 08:27 | You can see the X, Y and Z axis which are visible select any one of these axis in which you would like to view the stream lines. |
| 08:36 | I will select the Y axis and click ApplyYou can see the streamlines along the Y axis. |
| 08:44 | Similarly you can select the X axis and plot the streamlines along the X axisNow delete this. |
| 08:53 | 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 |
| 09:06 | Save the data as .(dot) csv file from file menu Click on save data |
| 09:13 | You can plot this data in libreoffice spreadsheet or any other plotting software of your choice.Now let me switch back to the slides |
| 09:23 | The results obtained can be validated by using results of Ghia et.al for Reynolds No , Re= 10000 |
| 09:32 | Thats all we have in this tutorial Let us summarise |
| 09:34 | Turbulent Flow in a Lid Driven Cavity And plotting streamlines in paraViewThis brings us to the end of the tutorial |
| 09:44 | As an assignment Modify the grid size of the cavity Change it to (100 100 1) and Visualise the results in paraview using streamlines |
| 09:55 | Watch the video available at this URLhttp://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. |
| 10:05 | 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 contact@spoken-tutorial.org |
| 10:20 | Spoken Tutorials project is a part of Talk to a Teacher project, It is supported by the National Mission on Education through ICT, MHRD, Government of India. |
| 10:30 | More information on the same is available at the following URL link http://spoken-tutorial.org/NMEICT-Intro |
| 10:34 | The script is contributed by Shekhar Mishra and Chaitanya talnikar.This is Rahul Joshi from IIT BOMBAY signing off.Thanks for joining |
