Difference between revisions of "OpenFOAM/C2/Simulating-flow-in-a-Lid-Driven-Cavity/English-timed"

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|-
 
|-
 
|  00:09
 
|  00:09
|The''' Lid Driven Cavity''' file structure
+
| The''' Lid Driven Cavity''' file structure
  
 
|-
 
|-
 
|  00:12
 
|  00:12
|'''Meshing '''the Geometry  
+
| '''Meshing '''the Geometry  
  
 
|-
 
|-
 
|  00:14
 
|  00:14
|Solving and post-processing results in '''Paraview'''
+
|Solving and post-processing results in '''Paraview'''
  
 
|-
 
|-
 
|  00:17
 
|  00:17
|Plotting & validating results on a spreadsheet.  
+
| Plotting & validating results on a spreadsheet.  
  
 
|-
 
|-
 
|  00:21
 
|  00:21
|  To record this tutorial,  
+
|  To record this tutorial, I am using: '''Linux Operating system Ubuntu''' version 10.04  
 
+
|-
+
|  00:22
+
I am using: '''Linux Operating system Ubuntu''' version 10.04  
+
  
 
|-
 
|-
Line 41: Line 37:
 
|-
 
|-
 
|  00:32
 
|  00:32
 +
|  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.
 +
 +
|-
 +
|  00:37
 
|  '''Lid driven cavity''' is the most widely used 2D test  
 
|  '''Lid driven cavity''' is the most widely used 2D test  
  
 
|-
 
|-
|  00:36
+
|  00:41
 
|  case for validation of a '''CFD code'''.
 
|  case for validation of a '''CFD code'''.
  
 
|-
 
|-
|  00:39
+
|  00:44
 
| This is the diagram of '''Lid Driven Cavity''',
 
| This is the diagram of '''Lid Driven Cavity''',
  
 
|-
 
|-
| 00:41
+
| 00:46
 
| the '''boundary conditions''' remain the same.
 
| the '''boundary conditions''' remain the same.
  
 
|-
 
|-
| 00:44
+
| 00:49
 
| A '''moving wall''' and '''three fixedwalls'''.
 
| A '''moving wall''' and '''three fixedwalls'''.
  
 
|-
 
|-
|  00:46
+
|  00:51
 
|  We are solving this for '''Reynolds no (Re) = 100'''.
 
|  We are solving this for '''Reynolds no (Re) = 100'''.
  
 
|-
 
|-
| 00:50
+
| 00:56
 
| The '''moving wall''' has a velocity of 1 meter per second.
 
| The '''moving wall''' has a velocity of 1 meter per second.
  
 
|-
 
|-
| 00:54
+
| 01:01
|   The '''path''' for the '''Lid Driven Cavity''' is the same as discussed in the installation tutorial.
+
| The '''path''' for the '''Lid Driven Cavity''' is the same as discussed in the installation tutorial.
  
 
|-
 
|-
|01:00
+
|01:05
 
|  Now, open a '''command terminal'''.   
 
|  Now, open a '''command terminal'''.   
  
 
|-
 
|-
| 01:02
+
| 01:07
| To do this, press '''Ctrl+Alt+t ''' keys simultaneously on your keyboard.
+
| To do this, press '''Ctrl+Alt+t ''' keys simultaneously on your keyboard.
  
 
|-
 
|-
|  01:08
+
|  01:13
|  In the command terminal, type the '''path''' for the '''lid driven cavity'''
+
|  In the command terminal
  
 
|-
 
|-
| 01:12
+
| 01:17
 
|and type "run" and press '''Enter'''.
 
|and type "run" and press '''Enter'''.
  
 
|-
 
|-
|01:15
+
|01:20
 
|  '''cd (space) tutorials''' and press '''Enter'''.
 
|  '''cd (space) tutorials''' and press '''Enter'''.
  
 
|-
 
|-
| 01:20
+
| 01:25
 
| '''cd '''(space)''' incompressible''' and press '''Enter'''.
 
| '''cd '''(space)''' incompressible''' and press '''Enter'''.
  
 
|-
 
|-
| 01:26
+
| 01:31
 
|'''cd '''(space)''' icoFoam '''(Note that F here is capital) and press '''Enter'''.
 
|'''cd '''(space)''' icoFoam '''(Note that F here is capital) and press '''Enter'''.
  
 
|-
 
|-
| 01:33
+
| 01:38
 
|  '''cd '''(space) '''cavity''' and press '''Enter'''.
 
|  '''cd '''(space) '''cavity''' and press '''Enter'''.
  
 
|-
 
|-
| 01:38
+
| 01:43
 
|Now, type "ls" and press '''Enter'''.
 
|Now, type "ls" and press '''Enter'''.
  
 
|-
 
|-
| 01:41
+
| 01:46
 
|In the file structure of '''cavity''', you will see 3 folders : '''0 , constant , and system'''.
 
|In the file structure of '''cavity''', you will see 3 folders : '''0 , constant , and system'''.
  
 
|-
 
|-
|01:46
+
|01:51
 
|  Now, type '''cd''' (space) '''constant''' and press '''Enter'''.
 
|  Now, type '''cd''' (space) '''constant''' and press '''Enter'''.
  
 
|-
 
|-
| 01:52
+
| 01:57
 
| Now type "ls" and press '''Enter'''.
 
| Now type "ls" and press '''Enter'''.
  
 
|-
 
|-
|01:55
+
|02:00
 
|  The '''constant''' folder contains another folder named '''polyMesh''' and a file describing the physical properties of fluid.
 
|  The '''constant''' folder contains another folder named '''polyMesh''' and a file describing the physical properties of fluid.
  
 
|-
 
|-
| 02:01
+
| 02:06
 
| Now, type '''cd (space) polymesh''' and Press '''Enter'''.
 
| Now, type '''cd (space) polymesh''' and Press '''Enter'''.
  
 
|-
 
|-
| 02:08
+
| 02:13
 
| '''PolyMesh''' contains a file named 'blockMeshDict'.
 
| '''PolyMesh''' contains a file named 'blockMeshDict'.
  
 
|-
 
|-
| 02:12
+
| 02:17
 
|  Now type "ls" and press '''Enter'''.
 
|  Now type "ls" and press '''Enter'''.
  
 
|-
 
|-
| 02:15
+
| 02:20
 
|  You can see the '''blockMeshDict'''
 
|  You can see the '''blockMeshDict'''
  
 
|-
 
|-
|  02:17
+
|  02:22
 
| To open up the  '''blockMeshDict''' file,  type '''gedit space blockMeshDict'''.
 
| To open up the  '''blockMeshDict''' file,  type '''gedit space blockMeshDict'''.
 
+
(Note that M and D  here are capital).Now press '''Enter'''.
(Note that M and D  here are capital)
+
 
+
Now press '''Enter'''.
+
  
 
|-
 
|-
| 02:30
+
| 02:35
 
|  This will Open up the '''blockMeshDict''' file.
 
|  This will Open up the '''blockMeshDict''' file.
  
 
|-
 
|-
| 02:32
+
| 02:37
 
| Let me drag this to the capture area.
 
| Let me drag this to the capture area.
  
 
|-
 
|-
|  02:36
+
|  02:41
 
|  This contains: coordinates for the '''lid driven cavity''',
 
|  This contains: coordinates for the '''lid driven cavity''',
  
 
|-
 
|-
|  02:41
+
|  02:46
 
|'''blocking''' and '''meshing parameters'''
 
|'''blocking''' and '''meshing parameters'''
  
 
|-
 
|-
|  02:44
+
|  02:49
 
|and '''boundary patches.'''
 
|and '''boundary patches.'''
  
 
|-
 
|-
|  02:47
+
|  02:52
 
| Since there are  no '''arcs''' as well as no '''patches''' to be merged, '''edges''' and '''mergePatchPairs''' can be kept empty.
 
| Since there are  no '''arcs''' as well as no '''patches''' to be merged, '''edges''' and '''mergePatchPairs''' can be kept empty.
  
 
|-
 
|-
| 02:56
+
| 03:01
 
| Now close this.
 
| Now close this.
  
 
|-
 
|-
02:58
+
03:03
 
|  In the command terminal, type : '''cd (space) .. (dot) (dot)'''  and press '''Enter.'''
 
|  In the command terminal, type : '''cd (space) .. (dot) (dot)'''  and press '''Enter.'''
  
 
|-
 
|-
| 03:04
+
| 03:09
 
| Do  this twice. You will come back to the''' cavity''' folder.
 
| Do  this twice. You will come back to the''' cavity''' folder.
  
 
|-
 
|-
| 03:09
+
| 03:14
 
|  Now, type '''cd''' (space) '''system''' and press '''Enter'''.
 
|  Now, type '''cd''' (space) '''system''' and press '''Enter'''.
  
 
|-
 
|-
|03:15
+
|03:20
 
|  Now type "ls", press '''Enter'''.  This contains three files-
 
|  Now type "ls", press '''Enter'''.  This contains three files-
  
 
|-
 
|-
|  03:22
+
|  03:27
 
|'''controlDict, fvSchemes''' and '''fvSolutions'''.
 
|'''controlDict, fvSchemes''' and '''fvSolutions'''.
  
 
|-
 
|-
|  03:26
+
|  03:31
 
| '''controlDict''' contains '''control parameters''' for start/end time.
 
| '''controlDict''' contains '''control parameters''' for start/end time.
 
  
 
|-
 
|-
|  03:30
+
|  03:35
 
|'''fvSolution''' contains '''discritization schemes''' used in '''run time'''.
 
|'''fvSolution''' contains '''discritization schemes''' used in '''run time'''.
  
 
|-
 
|-
|  03:35
+
|  03:40
 
|And, '''fvSchemes''' contains equation for '''solvers''', '''tolerance''' etc.  
 
|And, '''fvSchemes''' contains equation for '''solvers''', '''tolerance''' etc.  
  
 
|-
 
|-
| 03:40
+
| 03:45
 
| Now, again type '''cd (space) (dot dot) .. '''and press '''Enter'''.
 
| Now, again type '''cd (space) (dot dot) .. '''and press '''Enter'''.
  
 
|-
 
|-
| 03:46
+
| 03:51
 
|  Now type '''cd ( space )''' 0 (zero) and Press '''Enter'''.
 
|  Now type '''cd ( space )''' 0 (zero) and Press '''Enter'''.
  
 
|-
 
|-
|03:53
+
|03:58
 
| Now type "ls" and press '''Enter'''.
 
| Now type "ls" and press '''Enter'''.
  
 
|-
 
|-
| 03:57
+
| 04:02
 
|  This contains the initial values for '''boundary conditions''' like '''Pressure, Velocity, Temperature''' etc.  
 
|  This contains the initial values for '''boundary conditions''' like '''Pressure, Velocity, Temperature''' etc.  
  
 
|-
 
|-
|  04:03
+
|  04:08
 
| Now type''' cd ( space ) (dot dot) . .''' to return back to the '''cavity''' folder.
 
| Now type''' cd ( space ) (dot dot) . .''' to return back to the '''cavity''' folder.
  
 
|-
 
|-
| 04:09
+
| 04:14
 
|  Now we need to '''mesh '''the geometry.
 
|  Now we need to '''mesh '''the geometry.
  
 
|-
 
|-
|  04:11
+
|  04:16
 
|We are using a coarse mesh here.
 
|We are using a coarse mesh here.
  
 
|-
 
|-
|  04:14
+
|  04:19
 
|  '''Mesh''' the geometry by typing '''blockMesh''' in the '''terminal'''.
 
|  '''Mesh''' the geometry by typing '''blockMesh''' in the '''terminal'''.
  
 
|-
 
|-
|04:18
+
|04:23
 
| Now type '''blockMesh '''(Note that M  here is capital) and press '''Enter'''.
 
| Now type '''blockMesh '''(Note that M  here is capital) and press '''Enter'''.
  
 
|-
 
|-
| 04:25
+
| 04:30
 
|  The '''Meshing''' is done.
 
|  The '''Meshing''' is done.
  
 
|-
 
|-
| 04:27
+
| 04:32
 
| If there are some '''errors''' in the '''blockMesh''' file, it will be shown in the '''terminal'''.
 
| If there are some '''errors''' in the '''blockMesh''' file, it will be shown in the '''terminal'''.
  
 
|-
 
|-
|  04:31
+
|  04:36
|  To view the geometry,  
+
|  To view the geometry,type '''paraFoam'''. Note that 'F' here is capital and press '''Enter'''.
 
+
|-
+
|  04:32
+
|type '''paraFoam'''. Note that 'F' here is capital and press '''Enter'''.
+
  
 
|-
 
|-
|  04:40
+
|  04:45
 
|  This will open the '''paraview window'''.
 
|  This will open the '''paraview window'''.
  
 
|-
 
|-
|  04:44
+
|  04:49
 
|  Now on the left hand side of the '''object inspector''' menu, click on '''Apply.'''
 
|  Now on the left hand side of the '''object inspector''' menu, click on '''Apply.'''
  
 
|-
 
|-
| 04:49
+
| 04:54
 
| You can see the '''lid driven cavity''' geometry. Now close this.
 
| You can see the '''lid driven cavity''' geometry. Now close this.
  
 
|-
 
|-
|04:58
+
|05:03
 
|  Check the mesh by typing "checkMesh" in the terminal.
 
|  Check the mesh by typing "checkMesh" in the terminal.
  
 
|-
 
|-
|  05:04
+
|  05:09
 
|Note that 'M' here is capital and press '''Enter'''.
 
|Note that 'M' here is capital and press '''Enter'''.
  
 
|-
 
|-
|05:08
+
|05:13
 
| you can see  the number of cells, '''skewness''' and other parameters which are associated with the '''mesh'''.
 
| you can see  the number of cells, '''skewness''' and other parameters which are associated with the '''mesh'''.
  
 
|-
 
|-
|05:15
+
|05:20
 
|  Let me switch back to the '''slides'''.
 
|  Let me switch back to the '''slides'''.
  
 
|-
 
|-
|  05:17
+
|  05:22
 
|  The solver we are using here is '''icoFoam''':
 
|  The solver we are using here is '''icoFoam''':
  
 
|-
 
|-
|  05:20
+
|  05:25
 
|  '''icoFoam''' is a '''Transient solver''' for '''incompressible flow''' of '''newtonian fluids'''.
 
|  '''icoFoam''' is a '''Transient solver''' for '''incompressible flow''' of '''newtonian fluids'''.
  
 
|-
 
|-
|  05:26
+
|  05:31
 
|  Let me switch back to the terminal.
 
|  Let me switch back to the terminal.
  
 
|-
 
|-
|  05:29
+
|  05:34
 
|  In the terminal, type "icoFoam".  
 
|  In the terminal, type "icoFoam".  
  
 
|-
 
|-
|  05:33
+
|  05:38
 
|Note that 'F' here is capital and press '''Enter'''.
 
|Note that 'F' here is capital and press '''Enter'''.
  
 
|-
 
|-
|  05:37
+
|  05:42
 
| The  '''Iterations '''running will be seen in the terminal window.
 
| The  '''Iterations '''running will be seen in the terminal window.
  
 
|-
 
|-
| 05:40
+
| 05:45
 
| After the solving is done, type '''paraFoam''' in the terminal to view the geometry and the results.
 
| After the solving is done, type '''paraFoam''' in the terminal to view the geometry and the results.
  
 
|-
 
|-
| 05:54
+
| 05:59
 
|  On the left hand side of '''object inspector''' menu
 
|  On the left hand side of '''object inspector''' menu
  
 
|-
 
|-
05:57
+
06:02
|click on '''Apply'''.
+
|click on '''Apply'''.Now '''Scroll''' down the properties on '''object inspector''' menu.  
  
 
|-
 
|-
|  05:58
+
|  06:07
|  Now '''Scroll''' down the properties on '''object inspector''' menu.
+
 
+
|-
+
|  06:02
+
 
|you can see '''mesh parts, Volume Fields''' etc.
 
|you can see '''mesh parts, Volume Fields''' etc.
  
 
|-
 
|-
| 06:07
+
| 06:12
 
|  Check or uncheck these '''boxes''' in the '''mesh''' part, to view the different boundary regions of '''Lid driven cavity'''.
 
|  Check or uncheck these '''boxes''' in the '''mesh''' part, to view the different boundary regions of '''Lid driven cavity'''.
  
 
|-
 
|-
|   06:15
+
| 06:20
| Now, after this, on top of the left-hand side on  '''active variable control ''' drop-down menu, change this from '''solid color''' to '''p''' or capital '''U''' which are the '''initial conditions''' such as '''pressure, velocity'''.
+
| Now, after this, on top of the left-hand side on  '''active variable control ''' drop-down menu, change this from '''solid color''' to '''p''' or capital '''U''' which are the '''initial conditions''' such as '''pressure, velocity'''.
  
 
|-
 
|-
|  06:31
+
|  06:36
 
|I will select capital 'U'. Now this will show you the initial condition of velocity.  
 
|I will select capital 'U'. Now this will show you the initial condition of velocity.  
  
 
|-
 
|-
|  06:37
+
|  06:42
 
|  On top of the''' paraview''' window, you will see the''' VCR control'''.
 
|  On top of the''' paraview''' window, you will see the''' VCR control'''.
  
 
|-
 
|-
|  06:44
+
|  06:49
 
|Click on the '''play''' button.
 
|Click on the '''play''' button.
  
 
|-
 
|-
|  06:47
+
|  06:52
 
|  Now this is the final result of '''velocity''' for the '''lid driven cavity'''.
 
|  Now this is the final result of '''velocity''' for the '''lid driven cavity'''.
  
 
|-
 
|-
| 06:52
+
| 06:57
 
| Toggle on the '''color legend''' by clicking on  the top left of the '''active variable control''' menu.
 
| Toggle on the '''color legend''' by clicking on  the top left of the '''active variable control''' menu.
  
 
|-
 
|-
|  07:03
+
|  07:08
 
| This is the''' color legend''' for '''U velocity'''.
 
| This is the''' color legend''' for '''U velocity'''.
  
 
|-
 
|-
| 07:07
+
| 07:12
 
| We need to validate the results obtained.
 
| We need to validate the results obtained.
 
  
 
|-
 
|-
|  07:09
+
|  07:14
 
|To do this, let us plot the '''U''' and '''V velocity'''.
 
|To do this, let us plot the '''U''' and '''V velocity'''.
 
   
 
   
 
|-
 
|-
|  07:12
+
|  07:17
 
| To do this, go to '''Filters''' scroll down > '''Data Analysis''' > '''Plot Over line'''.
 
| To do this, go to '''Filters''' scroll down > '''Data Analysis''' > '''Plot Over line'''.
  
 
|-
 
|-
|  07:21
+
|  07:26
 
| Click on it.
 
| Click on it.
  
 
|-
 
|-
| 07:23
+
| 07:30
 
|  You can see  X , Y and Z axes.
 
|  You can see  X , Y and Z axes.
  
 
|-
 
|-
| 07:25
+
| 07:33
 
|  Select the '''X & Y axis''' turn by turn.
 
|  Select the '''X & Y axis''' turn by turn.
  
 
|-
 
|-
|  07:31
+
|  07:39
 
|I will select the '''X axis''' and click '''Apply'''.
 
|I will select the '''X axis''' and click '''Apply'''.
  
 
|-
 
|-
| 07:37
+
| 07:45
 
|  You can see '''Pressure''' and '''velocity''' '''plots''' being plotted.
 
|  You can see '''Pressure''' and '''velocity''' '''plots''' being plotted.
  
 
|-
 
|-
| 07:42
+
| 07:50
 
|  Since it is a non dimensional analysis, we need to plot the graph for '''u/U v/s y/L''' for '''Reynolds number =100'''
 
|  Since it is a non dimensional analysis, we need to plot the graph for '''u/U v/s y/L''' for '''Reynolds number =100'''
  
 
|-
 
|-
| 07:52
+
| 08:00
 
|  To do this, in '''Plot Data''' click on the '''Y-axis'''
 
|  To do this, in '''Plot Data''' click on the '''Y-axis'''
  
 
|-
 
|-
07:58
+
08:06
 
|and click '''APPLY'''.
 
|and click '''APPLY'''.
  
 
|-
 
|-
| 08:01
+
| 08:09
 
|  You can see the''' plot'''.
 
|  You can see the''' plot'''.
  
 
|-
 
|-
|  08:03
+
|  08:11
 
|Now in menu bar, go to '''File > Save Data'''.
 
|Now in menu bar, go to '''File > Save Data'''.
  
 
|-
 
|-
| 08:09
+
| 08:15
 
| Give  appropriate name to your file.
 
| Give  appropriate name to your file.
  
 
|-
 
|-
|  08:11
+
|  08:19
 
|  I will give this as "cavity".
 
|  I will give this as "cavity".
  
 
|-
 
|-
|  08:15
+
|  08:23
 
|The file will be saved as ".csv" (dot csv) file.
 
|The file will be saved as ".csv" (dot csv) file.
  
 
|-
 
|-
|  08:19
+
|  08:27
 
| Now click OK. Again click OK.
 
| Now click OK. Again click OK.
  
 
|-
 
|-
| 08:23
+
| 08:31
 
|  Now go to the '''cavity''' folder of '''openfoam directory'''.
 
|  Now go to the '''cavity''' folder of '''openfoam directory'''.
  
 
|-
 
|-
|  08:29
+
|  08:37
 
|Scroll down. you can see the '''cavity.csv''' file.
 
|Scroll down. you can see the '''cavity.csv''' file.
  
 
|-
 
|-
| 08:34
+
| 08:42
 
| Open it in '''Open office''' or '''LibreOffice Spreadsheet'''.
 
| Open it in '''Open office''' or '''LibreOffice Spreadsheet'''.
  
 
|-
 
|-
|  08:39
+
|  08:47
| In the LibreOffice spreadsheet, copy the U0 (u velocity) and to the right points 1(Y-axis) columns
+
| In the LibreOffice spreadsheet, copy the U0 (u velocity) and to the right points 1(Y-axis) columns in another spreadsheet.  
in another spreadsheet.  
+
  
 
|-
 
|-
|  08:48
+
|  08:56
 
|  Now, divide both these columns, that is, '''u zero''' by capital U and '''points 1''' by capital L
 
|  Now, divide both these columns, that is, '''u zero''' by capital U and '''points 1''' by capital L
  
 
|-
 
|-
08:59
+
09:07
 
| and plot the results in '''libreoffice''' charts option on top, in the menu bar.
 
| and plot the results in '''libreoffice''' charts option on top, in the menu bar.
  
 
|-
 
|-
|  09:08
+
|  09:16
 
| Now let me switch back to the slides.
 
| Now let me switch back to the slides.
  
 
|-
 
|-
|  09:10
+
|  09:18
 
| Results obtained will be similar to this figure.
 
| Results obtained will be similar to this figure.
  
 
|-
 
|-
| 09:16
+
| 09:24
| '''Validate''' the results on a  paper published on '''Lid Driven Cavity by : Ghia et al. (1982''') and  
+
| '''Validate''' the results on a  paper published on '''Lid Driven Cavity by : Ghia et al. (1982''') and Results obtained from Fluent.
Results obtained from Fluent.
+
  
 
|-
 
|-
|09:24  
+
|09:34  
 
|  In this tutorial, we learnt:   
 
|  In this tutorial, we learnt:   
  
 
|-
 
|-
|  09:26
+
|  09:36
|* File structure of '''Lid Driven cavity'''
+
| File structure of '''Lid Driven cavity'''
  
 
|-
 
|-
|  09:28
+
|  09:38
|* '''Solved lid driven cavity'''.
+
| '''Solved lid driven cavity'''.
  
 
|-
 
|-
|  09:30
+
|  09:40
|* '''Post-processing of solutions'''
+
|'''Post-processing of solutions'''
  
 
|-
 
|-
|  09:32
+
|  09:42
 
|And '''Validation'''.
 
|And '''Validation'''.
  
 
|-
 
|-
| 09:34
+
| 09:44
|   As an assignment,  
+
| As an assignment, Change some parameters in the '''lid driven cavity'''.
  
 
|-
 
|-
|  09:35
+
|  09:48
|Change some parameters in the '''lid driven cavity'''.
+
|'''Velocity Magnitude''' in the '''0 folder'''.
  
 
|-
 
|-
|  09:38
+
|  09:51
|* '''Velocity Magnitude''' in the '''0 folder'''.
+
| '''Kinematic viscosity'''  in '''transport Properties''' in '''constant''' folder.
|-
+
|  09:41
+
|* '''Kinematic viscosity'''  in '''transport Properties''' in '''constant''' folder.
+
  
 
|-
 
|-
|  09:45
+
|  09:55
 
|And, plot results of '''u/U and y/L'''.
 
|And, plot results of '''u/U and y/L'''.
  
 
|-
 
|-
| 09:50
+
| 10:00
| Watch the  video available at this URL:  
+
| Watch the  video available at this URL: http://spoken-tutorial.org/What_is_a_Spoken_Tutorial  
http://spoken-tutorial.org/What_is_a_Spoken_Tutorial  
+
  
 
|-
 
|-
09:54
+
10:04
 
|It summarizes the '''Spoken Tutorial''' project.  
 
|It summarizes the '''Spoken Tutorial''' project.  
  
 
|-
 
|-
09:57
+
10:07
 
|If you do not have good bandwidth, you can download and watch it.
 
|If you do not have good bandwidth, you can download and watch it.
  
 
|-
 
|-
|  10:00
+
|  10:10
 
|  The Spoken Tutorial project team:
 
|  The Spoken Tutorial project team:
  
 
|-
 
|-
|  10:02
+
|  10:12
|* Conducts workshops using spoken tutorials
+
|Conducts workshops using spoken tutorials
  
 
|-
 
|-
|  10:05
+
|  10:15
|* Gives certificates to those who pass an online test.
+
|Gives certificates to those who pass an online test.
  
 
|-
 
|-
|  10:09
+
|  10:19
|For more details, please write to us at:
+
|For more details, please write to us at:contact@spoken-tutorial.org
contact@spoken-tutorial.org
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|-
 
|-
| 10:15
+
| 10:40
 
| '''Spoken Tutorials''' are part of '''Talk to a Teacher''' project.  
 
| '''Spoken Tutorials''' are part of '''Talk to a Teacher''' project.  
  
 
|-
 
|-
|  10:18
+
|  10:43
 
|It is supported by the National Mission on Education through ICT, MHRD, Government of India.  
 
|It is supported by the National Mission on Education through ICT, MHRD, Government of India.  
  
 
|-
 
|-
|  10:23
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|  10:48
 
|More information on the same is available at the following URL:  http://spoken-tutorial.org/NMEICT-Intro
 
|More information on the same is available at the following URL:  http://spoken-tutorial.org/NMEICT-Intro
  
 
|-
 
|-
| 10:27
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| 10:52
 
|  This is Rahul Joshi from IIT Bombay, signing off.
 
|  This is Rahul Joshi from IIT Bombay, signing off.
  
 
|-
 
|-
|  10:30
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|  10:55
 
|Thanks for joining.
 
|Thanks for joining.
  
 
|}
 
|}

Latest revision as of 13:00, 9 April 2019

Time Narration
00:01 Hello and welcome to the spoken tutorial on Simulating Flow in a Lid Driven Cavity using openFoam.
00:07 In this tutorial, I will show you:
00:09 The Lid Driven Cavity file structure
00:12 Meshing the Geometry
00:14 Solving and post-processing results in Paraview
00:17 Plotting & validating results on a spreadsheet.
00:21 To record this tutorial, I am using: Linux Operating system Ubuntu version 10.04
00:27 OpenFOAM version 2.1.0 and ParaView version 3.12.0.
00:32 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.
00:37 Lid driven cavity is the most widely used 2D test
00:41 case for validation of a CFD code.
00:44 This is the diagram of Lid Driven Cavity,
00:46 the boundary conditions remain the same.
00:49 A moving wall and three fixedwalls.
00:51 We are solving this for Reynolds no (Re) = 100.
00:56 The moving wall has a velocity of 1 meter per second.
01:01 The path for the Lid Driven Cavity is the same as discussed in the installation tutorial.
01:05 Now, open a command terminal.
01:07 To do this, press Ctrl+Alt+t keys simultaneously on your keyboard.
01:13 In the command terminal
01:17 and type "run" and press Enter.
01:20 cd (space) tutorials and press Enter.
01:25 cd (space) incompressible and press Enter.
01:31 cd (space) icoFoam (Note that F here is capital) and press Enter.
01:38 cd (space) cavity and press Enter.
01:43 Now, type "ls" and press Enter.
01:46 In the file structure of cavity, you will see 3 folders : 0 , constant , and system.
01:51 Now, type cd (space) constant and press Enter.
01:57 Now type "ls" and press Enter.
02:00 The constant folder contains another folder named polyMesh and a file describing the physical properties of fluid.
02:06 Now, type cd (space) polymesh and Press Enter.
02:13 PolyMesh contains a file named 'blockMeshDict'.
02:17 Now type "ls" and press Enter.
02:20 You can see the blockMeshDict
02:22 To open up the blockMeshDict file, type gedit space blockMeshDict.

(Note that M and D here are capital).Now press Enter.

02:35 This will Open up the blockMeshDict file.
02:37 Let me drag this to the capture area.
02:41 This contains: coordinates for the lid driven cavity,
02:46 blocking and meshing parameters
02:49 and boundary patches.
02:52 Since there are no arcs as well as no patches to be merged, edges and mergePatchPairs can be kept empty.
03:01 Now close this.
03:03 In the command terminal, type : cd (space) .. (dot) (dot) and press Enter.
03:09 Do this twice. You will come back to the cavity folder.
03:14 Now, type cd (space) system and press Enter.
03:20 Now type "ls", press Enter. This contains three files-
03:27 controlDict, fvSchemes and fvSolutions.
03:31 controlDict contains control parameters for start/end time.
03:35 fvSolution contains discritization schemes used in run time.
03:40 And, fvSchemes contains equation for solvers, tolerance etc.
03:45 Now, again type cd (space) (dot dot) .. and press Enter.
03:51 Now type cd ( space ) 0 (zero) and Press Enter.
03:58 Now type "ls" and press Enter.
04:02 This contains the initial values for boundary conditions like Pressure, Velocity, Temperature etc.
04:08 Now type cd ( space ) (dot dot) . . to return back to the cavity folder.
04:14 Now we need to mesh the geometry.
04:16 We are using a coarse mesh here.
04:19 Mesh the geometry by typing blockMesh in the terminal.
04:23 Now type blockMesh (Note that M here is capital) and press Enter.
04:30 The Meshing is done.
04:32 If there are some errors in the blockMesh file, it will be shown in the terminal.
04:36 To view the geometry,type paraFoam. Note that 'F' here is capital and press Enter.
04:45 This will open the paraview window.
04:49 Now on the left hand side of the object inspector menu, click on Apply.
04:54 You can see the lid driven cavity geometry. Now close this.
05:03 Check the mesh by typing "checkMesh" in the terminal.
05:09 Note that 'M' here is capital and press Enter.
05:13 you can see the number of cells, skewness and other parameters which are associated with the mesh.
05:20 Let me switch back to the slides.
05:22 The solver we are using here is icoFoam:
05:25 icoFoam is a Transient solver for incompressible flow of newtonian fluids.
05:31 Let me switch back to the terminal.
05:34 In the terminal, type "icoFoam".
05:38 Note that 'F' here is capital and press Enter.
05:42 The Iterations running will be seen in the terminal window.
05:45 After the solving is done, type paraFoam in the terminal to view the geometry and the results.
05:59 On the left hand side of object inspector menu
06:02 click on Apply.Now Scroll down the properties on object inspector menu.
06:07 you can see mesh parts, Volume Fields etc.
06:12 Check or uncheck these boxes in the mesh part, to view the different boundary regions of Lid driven cavity.
06:20 Now, after this, on top of the left-hand side on active variable control drop-down menu, change this from solid color to p or capital U which are the initial conditions such as pressure, velocity.
06:36 I will select capital 'U'. Now this will show you the initial condition of velocity.
06:42 On top of the paraview window, you will see the VCR control.
06:49 Click on the play button.
06:52 Now this is the final result of velocity for the lid driven cavity.
06:57 Toggle on the color legend by clicking on the top left of the active variable control menu.
07:08 This is the color legend for U velocity.
07:12 We need to validate the results obtained.
07:14 To do this, let us plot the U and V velocity.
07:17 To do this, go to Filters scroll down > Data Analysis > Plot Over line.
07:26 Click on it.
07:30 You can see X , Y and Z axes.
07:33 Select the X & Y axis turn by turn.
07:39 I will select the X axis and click Apply.
07:45 You can see Pressure and velocity plots being plotted.
07:50 Since it is a non dimensional analysis, we need to plot the graph for u/U v/s y/L for Reynolds number =100
08:00 To do this, in Plot Data click on the Y-axis
08:06 and click APPLY.
08:09 You can see the plot.
08:11 Now in menu bar, go to File > Save Data.
08:15 Give appropriate name to your file.
08:19 I will give this as "cavity".
08:23 The file will be saved as ".csv" (dot csv) file.
08:27 Now click OK. Again click OK.
08:31 Now go to the cavity folder of openfoam directory.
08:37 Scroll down. you can see the cavity.csv file.
08:42 Open it in Open office or LibreOffice Spreadsheet.
08:47 In the LibreOffice spreadsheet, copy the U0 (u velocity) and to the right points 1(Y-axis) columns in another spreadsheet.
08:56 Now, divide both these columns, that is, u zero by capital U and points 1 by capital L
09:07 and plot the results in libreoffice charts option on top, in the menu bar.
09:16 Now let me switch back to the slides.
09:18 Results obtained will be similar to this figure.
09:24 Validate the results on a paper published on Lid Driven Cavity by : Ghia et al. (1982) and Results obtained from Fluent.
09:34 In this tutorial, we learnt:
09:36 File structure of Lid Driven cavity
09:38 Solved lid driven cavity.
09:40 Post-processing of solutions
09:42 And Validation.
09:44 As an assignment, Change some parameters in the lid driven cavity.
09:48 Velocity Magnitude in the 0 folder.
09:51 Kinematic viscosity in transport Properties in constant folder.
09:55 And, plot results of u/U and y/L.
10:00 Watch the video available at this URL: http://spoken-tutorial.org/What_is_a_Spoken_Tutorial
10:04 It summarizes the Spoken Tutorial project.
10:07 If you do not have good bandwidth, you can download and watch it.
10:10 The Spoken Tutorial project team:
10:12 Conducts workshops using spoken tutorials
10:15 Gives certificates to those who pass an online test.
10:19 For more details, please write to us at:contact@spoken-tutorial.org
10:40 Spoken Tutorials are part of Talk to a Teacher project.
10:43 It is supported by the National Mission on Education through ICT, MHRD, Government of India.
10:48 More information on the same is available at the following URL: http://spoken-tutorial.org/NMEICT-Intro
10:52 This is Rahul Joshi from IIT Bombay, signing off.
10:55 Thanks for joining.

Contributors and Content Editors

DeepaVedartham, Gaurav, Nancyvarkey, PoojaMoolya, Sandhya.np14, Sneha