Difference between revisions of "OpenFOAM/C2/Creating-simple-geometry-in-OpenFOAM/English-timed"

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| 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.
 +
 
 +
|-
 +
| 00:30
 
| In '''CFD''' the Pre-processing part consists of  creating geometry and meshing it.  
 
| In '''CFD''' the Pre-processing part consists of  creating geometry and meshing it.  
  
 
|-
 
|-
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| Let us take the '''Lid driven cavity''' case of the previous tutorial as an example.  
 
| Let us take the '''Lid driven cavity''' case of the previous tutorial as an example.  
  
 
|-
 
|-
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| 00:41
| Recall the '''path''' for  the earlier tutorial.  
+
| Recall the '''path''' for  the earlier tutorial.
  
 
|-
 
|-
| 00:40
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| 00:44
| I have already opened the '''command terminal''' and entered  the '''path''' for '''lid driven cavity'''.  
+
| I have already opened the '''command terminal''' and entered  the '''path''' for '''lid driven cavity'''.
  
 
|-
 
|-
| 00:48
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| 00:48
 +
| To source the OpenFOAM version 5, type:$of5. To go to the run folder, type:$cd $FOAM_RUN. To open the cavity case directory, type:$cd tutorials/incompressible/icoFoam/cavity/cavity. To list the contents of case directory, type:$ls.
 +
 
 +
 
 +
|-
 +
|  00:54
 
| There are three folders '0, constant' and 'system'. 'Geometry' is inside the 'polymesh' folder of 'constant'.
 
| There are three folders '0, constant' and 'system'. 'Geometry' is inside the 'polymesh' folder of 'constant'.
  
 
|-
 
|-
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| 01:11
 
| In the command terminal, type: '''cd space constant''' and press '''Enter'''.
 
| In the command terminal, type: '''cd space constant''' and press '''Enter'''.
  
 
|-
 
|-
|  01:03
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|  01:19
 
| Now, type "ls" and press '''Enter'''.
 
| Now, type "ls" and press '''Enter'''.
  
 
|-
 
|-
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| 01:21
 
| In this, there is another folder called as 'polyMesh'.  
 
| In this, there is another folder called as 'polyMesh'.  
  
 
|-
 
|-
| 01:10
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| 01:26
 
|Now type: '''cd space polymesh''' and press '''Enter'''.
 
|Now type: '''cd space polymesh''' and press '''Enter'''.
  
 
|-
 
|-
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| 01:34
 
|Now type "ls" and press '''Enter'''.
 
|Now type "ls" and press '''Enter'''.
  
 
|-
 
|-
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| 01:39
 +
|To list the contents of the cavity directory, type:$ls. 0 constant system. To open the system directory, type:$cd system. To list the contents of the system directory, type:$ls blockMeshDict controlDict fvSchemes fvSolution.
 +
 
 +
|-
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| 01:45
 
| This contains the 'geometry' file called as 'blockMeshDict'.
 
| This contains the 'geometry' file called as 'blockMeshDict'.
  
 
|-
 
|-
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| 01:48
 
| Open the 'blockMeshDict' file with any '''editor''' of your choice.  
 
| Open the 'blockMeshDict' file with any '''editor''' of your choice.  
  
 
|-
 
|-
| 01:30
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| 01:52
 
| In the terminal, type: '''gedit space blockMeshDict'''( Note that M and D are capital) and press  '''Enter'''.
 
| In the terminal, type: '''gedit space blockMeshDict'''( Note that M and D are capital) and press  '''Enter'''.
  
 
|-
 
|-
| 01:45
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| 02:07
 
|Let me drag this to the capture area.
 
|Let me drag this to the capture area.
  
 
|-
 
|-
| 01:49
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| 02:11
 
|Now minimize this.  
 
|Now minimize this.  
  
 
|-
 
|-
01:53
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02:15
 
|  Let me switch back to the '''slide'''.  
 
|  Let me switch back to the '''slide'''.  
  
 
|-
 
|-
01:55
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02:17
 
| In '''openfoam''', the entire '''geometry''' is broken into '''blocks '''.
 
| In '''openfoam''', the entire '''geometry''' is broken into '''blocks '''.
  
 
|-
 
|-
01:59
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02:21
 
|  The blocks are numbered starting from 0 (zero) as shown in the figure.  
 
|  The blocks are numbered starting from 0 (zero) as shown in the figure.  
  
 
|-
 
|-
| 02:08
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| 02:30
 
| Note that in OpenFOAM, for creating a 2D geometry you need to give an  unit cell thickness value in the z-axis.
 
| Note that in OpenFOAM, for creating a 2D geometry you need to give an  unit cell thickness value in the z-axis.
  
 
|-
 
|-
| 02:19
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| 02:41
 
| '''lid driven cavity''' is of length 1 and height 1.  Minimize the slide.  
 
| '''lid driven cavity''' is of length 1 and height 1.  Minimize the slide.  
  
 
|-
 
|-
| 02:29
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| 02:51
 
|  On your desktop, create an empty file by right click > '''create document > Empty file'''. Name this as 'blockMeshDict'. (Note that M and D here are capital).
 
|  On your desktop, create an empty file by right click > '''create document > Empty file'''. Name this as 'blockMeshDict'. (Note that M and D here are capital).
  
 
|-
 
|-
| 02:48
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| 03:10
 
| Open this. Now, copy the data from the original '''lid driven cavity''' 'blockMeshDict' file to the new 'blockMeshDict' file from line 0.
 
| Open this. Now, copy the data from the original '''lid driven cavity''' 'blockMeshDict' file to the new 'blockMeshDict' file from line 0.
  
 
|-
 
|-
02:59
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03:21
 
| Scroll up line 0 upto 'convertTometers'. Copy this and '''paste''' it here.  
 
| Scroll up line 0 upto 'convertTometers'. Copy this and '''paste''' it here.  
  
 
|-
 
|-
|  03:15
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|  03:38
 
| Scroll down. Now leave some space after 'converttometers'.
 
| Scroll down. Now leave some space after 'converttometers'.
  
 
|-
 
|-
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|  03:44
 
|  Enter 1 as the geometry is in meters. Insert a semicolon and press  '''Enter'''.
 
|  Enter 1 as the geometry is in meters. Insert a semicolon and press  '''Enter'''.
  
 
|-
 
|-
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|  03:52
 
|Again press  '''Enter'''. In the file, type "vertices" and press  '''Enter'''.
 
|Again press  '''Enter'''. In the file, type "vertices" and press  '''Enter'''.
  
 
|-
 
|-
03:39
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04:01
 
| Insert the open bracket and press  '''Enter'''.
 
| Insert the open bracket and press  '''Enter'''.
  
 
|-
 
|-
03:43
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04:04
 
| Press the '''tab''' key. Start with point 0, insert open, close brackets,  '''Enter'''.
 
| Press the '''tab''' key. Start with point 0, insert open, close brackets,  '''Enter'''.
  
 
|-
 
|-
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| 04:14
 
| '''0 space 0 space 0 '''and press '''Enter'''. Again, press '''tab''' key, open close bracket .
 
| '''0 space 0 space 0 '''and press '''Enter'''. Again, press '''tab''' key, open close bracket .
  
 
|-
 
|-
|  04:02
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|  04:24
 
| Move towards point 1 in positive x-axis and enter ''' 1 space 0 space 0''' and press  '''Enter'''.
 
| Move towards point 1 in positive x-axis and enter ''' 1 space 0 space 0''' and press  '''Enter'''.
  
 
|-
 
|-
|  04:12
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|  04:34
 
|Again press the tab key, open close bracket. Move towards point 2 in the positive x-y plane and enter '''1 space 1 space 0''' and press '''Enter'''.
 
|Again press the tab key, open close bracket. Move towards point 2 in the positive x-y plane and enter '''1 space 1 space 0''' and press '''Enter'''.
  
 
|-
 
|-
|  04:26
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|  04:48
 
|Again press '''tab''' key, open close bracket. Enter the 3rd point in positive y-axis '''0 space 1 space 0 ''',  press  '''Enter'''.
 
|Again press '''tab''' key, open close bracket. Enter the 3rd point in positive y-axis '''0 space 1 space 0 ''',  press  '''Enter'''.
  
 
|-
 
|-
| 04:39
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| 05:01
 
| Again press the '''tab''' key. Enter the 4th point on the front face, open close bracket, '''0 space 0 space 0.1''' and press  '''Enter'''.
 
| Again press the '''tab''' key. Enter the 4th point on the front face, open close bracket, '''0 space 0 space 0.1''' and press  '''Enter'''.
  
 
|-
 
|-
04:51
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05:13
 
| Similarly, enter the other points with one unit value in the positive z- axis.  
 
| Similarly, enter the other points with one unit value in the positive z- axis.  
  
 
|-
 
|-
| 04:56
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| 05:19
 
| close the bracket and insert a semicolon after it. Press  '''Enter''', again press '''Enter'''.
 
| close the bracket and insert a semicolon after it. Press  '''Enter''', again press '''Enter'''.
  
 
|-
 
|-
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| 05:26
 
|  Below vertices are the blocks. Type blocks and  press  '''Enter'''. Insert a open bracket and press '''Enter'''.  
 
|  Below vertices are the blocks. Type blocks and  press  '''Enter'''. Insert a open bracket and press '''Enter'''.  
  
 
|-
 
|-
| 05:16
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| 05:39
 
|Let me switch back to the slides.
 
|Let me switch back to the slides.
  
 
|-
 
|-
| 05:19
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| 05:41
 
| Note that '''Lid driven cavity''' is taken as a single block.
 
| Note that '''Lid driven cavity''' is taken as a single block.
  
 
|-
 
|-
| 05:24
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| 05:46
 
| Let me switch back to 'blockmeshdict'.
 
| Let me switch back to 'blockmeshdict'.
  
 
|-
 
|-
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| 05:48
 
|Enter the points for the block in the clockwise sense.  
 
|Enter the points for the block in the clockwise sense.  
  
 
|-
 
|-
| 05:31
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| 05:53
 
|We are using here '''hexa hedral blocks '''for '''meshing.'''
 
|We are using here '''hexa hedral blocks '''for '''meshing.'''
  
 
|-
 
|-
| 05:34
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| 05:56
 
|Now, type "hex". Leave some space. In brackets, enter ''' 0  space 1 2 3 4 5 6 7  ''', again leave some space.
 
|Now, type "hex". Leave some space. In brackets, enter ''' 0  space 1 2 3 4 5 6 7  ''', again leave some space.
  
 
|-
 
|-
| 05:53
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| 06:15
 
| Note that for multiple blocks, the points will be more.  
 
| Note that for multiple blocks, the points will be more.  
  
 
|-
 
|-
05:58
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06:20
 
|After this, enter the '''grid''' points in the x, y and z directions.  
 
|After this, enter the '''grid''' points in the x, y and z directions.  
  
 
|-
 
|-
| 06:02
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| 06:25
 
|In brackets, open close brackets, enter '''30 space 30 space 1'''. Leave some space, you can  modify the grid as and when needed.  
 
|In brackets, open close brackets, enter '''30 space 30 space 1'''. Leave some space, you can  modify the grid as and when needed.  
  
 
|-
 
|-
|  06:16
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|  06:38
 
|Grid point in the z-axis can be taken as one.  
 
|Grid point in the z-axis can be taken as one.  
  
 
|-
 
|-
|  06:22
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|  06:44
 
|Now, leave some space and type "simple Grading". Leave some space, open close bracket, enter '''1 space 1 space 1 '''.
 
|Now, leave some space and type "simple Grading". Leave some space, open close bracket, enter '''1 space 1 space 1 '''.
  
 
|-
 
|-
| 06:36
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| 06:58
 
| This is the grid spacing in the x, y and z directions. Press  '''Enter'''.
 
| This is the grid spacing in the x, y and z directions. Press  '''Enter'''.
  
 
|-
 
|-
| 06:43
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| 07:05
 
| Insert close bracket, insert a semicolon and press  '''Enter'''.
 
| Insert close bracket, insert a semicolon and press  '''Enter'''.
  
 
|-
 
|-
| 06:48
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| 07:11
 
| Again press '''Enter'''. Now type "edges" and press  '''Enter'''.
 
| Again press '''Enter'''. Now type "edges" and press  '''Enter'''.
 
|-
 
|-
| 06:55
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| 07:17
 
|  As this is a simple geometry, '''edges''' can be kept empty.  
 
|  As this is a simple geometry, '''edges''' can be kept empty.  
  
 
|-
 
|-
| 07:00
+
| 07:21
 
|  Insert  open  bracket, press  '''Enter''',  close the  bracket. Insert  a semicolon and press  '''Enter'''.
 
|  Insert  open  bracket, press  '''Enter''',  close the  bracket. Insert  a semicolon and press  '''Enter'''.
  
 
|-
 
|-
|  07:07
+
|  07:28
 
| Again press  '''Enter'''. Below '''edges''' are the '''boundary conditions'''.  
 
| Again press  '''Enter'''. Below '''edges''' are the '''boundary conditions'''.  
  
 
|-
 
|-
|  07:11
+
|  07:33
 
| Here you need to enter the '''boundary names''' for the '''faces'''.
 
| Here you need to enter the '''boundary names''' for the '''faces'''.
  
 
|-
 
|-
|  07:15
+
|  07:37
 
|Type "boundary" and  press '''Enter''' .  
 
|Type "boundary" and  press '''Enter''' .  
  
 
|-
 
|-
| 07:19
+
| 07:41
 
|Insert an open bracket and press  '''Enter'''.
 
|Insert an open bracket and press  '''Enter'''.
  
 
|-
 
|-
| 07:23
+
| 07:45
 
|Now, let me switch back to the slides.  
 
|Now, let me switch back to the slides.  
  
 
|-
 
|-
|07:26  
+
|07:48  
 
|In the geometry, the upper wall is moving and other three walls are fixed.  
 
|In the geometry, the upper wall is moving and other three walls are fixed.  
  
 
|-
 
|-
| 07:31
+
| 07:53
 
| The front and back faces are named as 'empty' as this is a 2D problem.
 
| The front and back faces are named as 'empty' as this is a 2D problem.
  
 
|-
 
|-
| 07:39
+
| 08:01
 
| Open the new 'blockMeshDict' file again.
 
| Open the new 'blockMeshDict' file again.
  
 
|-
 
|-
|07:42
+
|08:04
 
| In '''boundary''', put the name of the '''patch''' as 'moving wall' . Press  '''Enter'''.
 
| In '''boundary''', put the name of the '''patch''' as 'moving wall' . Press  '''Enter'''.
  
 
|-
 
|-
| 07:51
+
| 08:16
 
| Now, insert a open curly bracket and press  '''Enter'''.
 
| Now, insert a open curly bracket and press  '''Enter'''.
  
 
|-
 
|-
| 07:56
+
| 08:20
 
| Now, enter the '''type''' for the '''moving wall''' , enter "type" space  "wall".   
 
| Now, enter the '''type''' for the '''moving wall''' , enter "type" space  "wall".   
  
 
|-
 
|-
| 08:06
+
| 08:28
 
| Insert a semicolon and press  '''Enter'''.
 
| Insert a semicolon and press  '''Enter'''.
  
 
|-
 
|-
| 08:09
+
| 08:33
|Now, insert open bracket and press '''Enter'''. Press the '''tab''' key, open close bracket.
+
|Now, faces, now press Enter, insert open bracket and press '''Enter'''. Press the '''tab''' key, open close bracket.
  
 
|-
 
|-
|  08:20
+
|  08:47
 
|In this bracket, enter the points for faces.
 
|In this bracket, enter the points for faces.
  
 
|-
 
|-
|  08:24
+
|  08:51
 
|Let me switch back to the slide.
 
|Let me switch back to the slide.
  
 
|-
 
|-
| 08:27
+
| 08:54
 
| Note that the order of the points  should be in such a way that the thumb should be normal to the face
 
| Note that the order of the points  should be in such a way that the thumb should be normal to the face
  
 
|-
 
|-
08:34
+
09:01
 
| and fingers making a  curl  as shown in the figure.
 
| and fingers making a  curl  as shown in the figure.
  
 
|-
 
|-
08:39
+
09:06
 
|The curl can be clockwise or anti-clockwise.  
 
|The curl can be clockwise or anti-clockwise.  
  
 
|-
 
|-
08:43
+
09:09
 
| Also note that the points should match with the points inserted in vertices.
 
| Also note that the points should match with the points inserted in vertices.
  
 
|-
 
|-
08:48
+
09:14
 
|Now, let me switch back to the new 'blockMeshDict' file.
 
|Now, let me switch back to the new 'blockMeshDict' file.
  
 
|-
 
|-
08:52
+
09:18
 
|Now in the faces, enter '''3 space 7 space 6 space 2'''.
 
|Now in the faces, enter '''3 space 7 space 6 space 2'''.
  
 
|-
 
|-
|  09:01
+
|  09:28
 
|  Let me switch back to the slide. These are the points for the moving wall 3, 7, 6, 2.
 
|  Let me switch back to the slide. These are the points for the moving wall 3, 7, 6, 2.
  
 
|-
 
|-
| 09:09
+
| 09:35
 
|Minimize this. Note that you can start from any point on that face. Now press  '''Enter'''.
 
|Minimize this. Note that you can start from any point on that face. Now press  '''Enter'''.
  
 
|-
 
|-
| 09:17
+
| 09:44
 
|Close the bracket. Again press  '''Enter'''. Close the curly bracket.
 
|Close the bracket. Again press  '''Enter'''. Close the curly bracket.
  
 
|-
 
|-
| 09:22
+
| 09:55
 
|Another note: we need to enter a semi colon after you insert the points for faces. Now after the curly brackets, press  '''Enter''', again press  '''Enter'''.
 
|Another note: we need to enter a semi colon after you insert the points for faces. Now after the curly brackets, press  '''Enter''', again press  '''Enter'''.
  
 
|-
 
|-
| 09:35
+
| 10:01
 
|Now, similarly enter '''boundary condition''' and '''faces''' for the '''fixed walls'''.
 
|Now, similarly enter '''boundary condition''' and '''faces''' for the '''fixed walls'''.
  
 
|-
 
|-
| 09:40
+
| 10:06
 
| Being a 2D problem the type of boundary for the front and back faces can be kept as empty.
 
| Being a 2D problem the type of boundary for the front and back faces can be kept as empty.
  
 
|-
 
|-
| 09:46
+
| 10:13
 
|Refer to the figure in the slide. For entering the points, minimize this.
 
|Refer to the figure in the slide. For entering the points, minimize this.
  
 
|-
 
|-
| 09:52
+
| 10:19
 
| Insert the closed brackets,  put a semicolon and press  '''Enter''',  again press  '''Enter'''.
 
| Insert the closed brackets,  put a semicolon and press  '''Enter''',  again press  '''Enter'''.
  
 
|-
 
|-
| 09:59
+
| 10:26
 
|Now type "mergePatchPairs" and press  '''Enter'''.
 
|Now type "mergePatchPairs" and press  '''Enter'''.
  
 
|-
 
|-
| 10:04
+
| 10:32
 
| Since there are no patches to be merged, it can be kept empty.
 
| Since there are no patches to be merged, it can be kept empty.
  
 
|-
 
|-
| 10:08
+
| 10:35
 
| Insert open close brackets. Insert a semicolon and press  '''Enter'''.
 
| Insert open close brackets. Insert a semicolon and press  '''Enter'''.
  
 
|-
 
|-
| 10:14
+
| 10:41
 
| We are done with creating the  'blockMeshDict' file. '''Save''' this.    
 
| We are done with creating the  'blockMeshDict' file. '''Save''' this.    
  
 
|-
 
|-
| 10:18
+
| 10:46
 
| The complete 'blockMeshDict' file is as shown here.  
 
| The complete 'blockMeshDict' file is as shown here.  
  
 
|-
 
|-
|10:26
+
|10:54
 
| Close  both the 'blockMeshDict' files.
 
| Close  both the 'blockMeshDict' files.
  
 
|-
 
|-
| 10:29
+
| 10:56
 
| Note that the '''command terminal''' will not work until the '''blockMeshDict''' file is closed.  
 
| Note that the '''command terminal''' will not work until the '''blockMeshDict''' file is closed.  
  
 
|-
 
|-
10:35
+
11:01
 
|  Switch back to the terminal. Now, type '''cd space (dot) (dot)''' twice to return back to the 'cavity' folder. Now '''Mesh the geometry'''.  
 
|  Switch back to the terminal. Now, type '''cd space (dot) (dot)''' twice to return back to the 'cavity' folder. Now '''Mesh the geometry'''.  
  
 
|-
 
|-
|10:45
+
|11:12
 
|To do this, on the terminal, type: "blockMesh" and press  '''Enter'''.
 
|To do this, on the terminal, type: "blockMesh" and press  '''Enter'''.
  
 
|-
 
|-
| 10:53
+
| 11:20
 
|Now, view the '''geometry''' by typing on the '''command terminal''' '''paraFoam''' and press  '''Enter'''.
 
|Now, view the '''geometry''' by typing on the '''command terminal''' '''paraFoam''' and press  '''Enter'''.
  
 
|-
 
|-
| 10:59
+
| 11:27
 
| This will open the ''' ParaView''' window.
 
| This will open the ''' ParaView''' window.
  
 
|-
 
|-
| 11:03
+
| 11:30
 
| Now, on the left hand side, click '''Apply''' on '''object inspector''' menu. Thus, you can see the geometry.
 
| Now, on the left hand side, click '''Apply''' on '''object inspector''' menu. Thus, you can see the geometry.
  
 
|-
 
|-
| 11:13
+
| 11:39
 
| Now, let me switch back to  the slides.
 
| Now, let me switch back to  the slides.
  
 
|-
 
|-
| 11:16
+
| 11:43
 
| In this tutorial, we learnt:  
 
| In this tutorial, we learnt:  
  
 
|-
 
|-
| 11:18
+
| 11:45
 
| Creating a simple geometry in '''OpenFOAM'''  
 
| Creating a simple geometry in '''OpenFOAM'''  
  
 
|-
 
|-
| 11:22
+
| 11:49
 
| Viewing the geometry in '''Paraview '''.
 
| Viewing the geometry in '''Paraview '''.
  
 
|-
 
|-
| 11:25
+
| 11:52
 
| This brings us to the end of the tutorial.  
 
| This brings us to the end of the tutorial.  
  
 
|-
 
|-
| 11:29
+
| 11:56
 
| As an Assignment-  
 
| As an Assignment-  
  
 
|-
 
|-
| 11:31
+
| 11:58
 
| Change the dimensions of the '''lid driven cavity''', change  the grid size to '''50 50 1''' and view the geometry in '''paraView'''.  
 
| Change the dimensions of the '''lid driven cavity''', change  the grid size to '''50 50 1''' and view the geometry in '''paraView'''.  
  
 
|-
 
|-
| 11:41
+
| 12:08
 
| Watch the video available at this URL: [http://spoken-tutorial.org/What_is_a_Spoken_Tutorial]
 
| Watch the video available at this URL: [http://spoken-tutorial.org/What_is_a_Spoken_Tutorial]
  
 
|-
 
|-
| 11:44
+
| 12:11
 
| It summarizes the Spoken Tutorial project.  
 
| It summarizes the Spoken Tutorial project.  
  
 
|-
 
|-
| 11:46
+
| 12:13
 
| If you do not have a good bandwidth, you can download and watch it.  
 
| If you do not have a good bandwidth, you can download and watch it.  
  
 
|-
 
|-
| 11:51
+
| 12:18
 
| The Spoken Tutorial project team:  
 
| The Spoken Tutorial project team:  
  
 
|-
 
|-
| 11:53
+
| 12:20
 
| Conducts workshops using spoken tutorials  
 
| Conducts workshops using spoken tutorials  
  
 
|-
 
|-
| 11:55
+
| 12:22
 
| Gives certificates to those who pass an online test.  
 
| Gives certificates to those who pass an online test.  
  
 
|-
 
|-
| 11:59
+
| 12:25
 
| For more details, please write to:
 
| For more details, please write to:
 
'''contact@spoken-tutorial.org'''  
 
'''contact@spoken-tutorial.org'''  
  
 
|-
 
|-
| 12:05
+
| 12:48
 
|  '''Spoken Tutorial''' project is part of the '''Talk to a Teacher''' project.  
 
|  '''Spoken Tutorial''' project is part of the '''Talk to a Teacher''' project.  
  
 
|-
 
|-
| 12:09
+
| 12:51
 
| 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.  
  
 
|-
 
|-
| 12:15
+
| 12:57
 
| More information on this mission is available at the following URL:
 
| More information on this mission is available at the following URL:
 
[http://spoken-tutorial.org/NMEICT-Intro]
 
[http://spoken-tutorial.org/NMEICT-Intro]
  
 
|-
 
|-
| 12:19
+
| 13:02
 
| | This is Rahul Joshi from '''IIT Bombay''', signing off. Thanks for joining.  
 
| | This is Rahul Joshi from '''IIT Bombay''', signing off. Thanks for joining.  
 
|}
 
|}

Latest revision as of 03:39, 13 March 2019

Time Narration
00:01 Hello and welcome to the spoken tutorial on creating simple geometry in OpenFOAM.
00:06 In this tutorial, I will show you:
00:08 How to create simple geometry
00:11 How to view the geometry in paraview.
00:15 To record this tutorial,I am using: Linux Operating system Ubuntu version 10.04 OpenFOAM version 2.1.0 ParaView version 3.12.0
00:26 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.
00:30 In CFD the Pre-processing part consists of creating geometry and meshing it.
00:37 Let us take the Lid driven cavity case of the previous tutorial as an example.
00:41 Recall the path for the earlier tutorial.
00:44 I have already opened the command terminal and entered the path for lid driven cavity.
00:48 To source the OpenFOAM version 5, type:$of5. To go to the run folder, type:$cd $FOAM_RUN. To open the cavity case directory, type:$cd tutorials/incompressible/icoFoam/cavity/cavity. To list the contents of case directory, type:$ls.


00:54 There are three folders '0, constant' and 'system'. 'Geometry' is inside the 'polymesh' folder of 'constant'.
01:11 In the command terminal, type: cd space constant and press Enter.
01:19 Now, type "ls" and press Enter.
01:21 In this, there is another folder called as 'polyMesh'.
01:26 Now type: cd space polymesh and press Enter.
01:34 Now type "ls" and press Enter.
01:39 To list the contents of the cavity directory, type:$ls. 0 constant system. To open the system directory, type:$cd system. To list the contents of the system directory, type:$ls blockMeshDict controlDict fvSchemes fvSolution.
01:45 This contains the 'geometry' file called as 'blockMeshDict'.
01:48 Open the 'blockMeshDict' file with any editor of your choice.
01:52 In the terminal, type: gedit space blockMeshDict( Note that M and D are capital) and press Enter.
02:07 Let me drag this to the capture area.
02:11 Now minimize this.
02:15 Let me switch back to the slide.
02:17 In openfoam, the entire geometry is broken into blocks .
02:21 The blocks are numbered starting from 0 (zero) as shown in the figure.
02:30 Note that in OpenFOAM, for creating a 2D geometry you need to give an unit cell thickness value in the z-axis.
02:41 lid driven cavity is of length 1 and height 1. Minimize the slide.
02:51 On your desktop, create an empty file by right click > create document > Empty file. Name this as 'blockMeshDict'. (Note that M and D here are capital).
03:10 Open this. Now, copy the data from the original lid driven cavity 'blockMeshDict' file to the new 'blockMeshDict' file from line 0.
03:21 Scroll up line 0 upto 'convertTometers'. Copy this and paste it here.
03:38 Scroll down. Now leave some space after 'converttometers'.
03:44 Enter 1 as the geometry is in meters. Insert a semicolon and press Enter.
03:52 Again press Enter. In the file, type "vertices" and press Enter.
04:01 Insert the open bracket and press Enter.
04:04 Press the tab key. Start with point 0, insert open, close brackets, Enter.
04:14 0 space 0 space 0 and press Enter. Again, press tab key, open close bracket .
04:24 Move towards point 1 in positive x-axis and enter 1 space 0 space 0 and press Enter.
04:34 Again press the tab key, open close bracket. Move towards point 2 in the positive x-y plane and enter 1 space 1 space 0 and press Enter.
04:48 Again press tab key, open close bracket. Enter the 3rd point in positive y-axis 0 space 1 space 0 , press Enter.
05:01 Again press the tab key. Enter the 4th point on the front face, open close bracket, 0 space 0 space 0.1 and press Enter.
05:13 Similarly, enter the other points with one unit value in the positive z- axis.
05:19 close the bracket and insert a semicolon after it. Press Enter, again press Enter.
05:26 Below vertices are the blocks. Type blocks and press Enter. Insert a open bracket and press Enter.
05:39 Let me switch back to the slides.
05:41 Note that Lid driven cavity is taken as a single block.
05:46 Let me switch back to 'blockmeshdict'.
05:48 Enter the points for the block in the clockwise sense.
05:53 We are using here hexa hedral blocks for meshing.
05:56 Now, type "hex". Leave some space. In brackets, enter 0 space 1 2 3 4 5 6 7 , again leave some space.
06:15 Note that for multiple blocks, the points will be more.
06:20 After this, enter the grid points in the x, y and z directions.
06:25 In brackets, open close brackets, enter 30 space 30 space 1. Leave some space, you can modify the grid as and when needed.
06:38 Grid point in the z-axis can be taken as one.
06:44 Now, leave some space and type "simple Grading". Leave some space, open close bracket, enter 1 space 1 space 1 .
06:58 This is the grid spacing in the x, y and z directions. Press Enter.
07:05 Insert close bracket, insert a semicolon and press Enter.
07:11 Again press Enter. Now type "edges" and press Enter.
07:17 As this is a simple geometry, edges can be kept empty.
07:21 Insert open bracket, press Enter, close the bracket. Insert a semicolon and press Enter.
07:28 Again press Enter. Below edges are the boundary conditions.
07:33 Here you need to enter the boundary names for the faces.
07:37 Type "boundary" and press Enter .
07:41 Insert an open bracket and press Enter.
07:45 Now, let me switch back to the slides.
07:48 In the geometry, the upper wall is moving and other three walls are fixed.
07:53 The front and back faces are named as 'empty' as this is a 2D problem.
08:01 Open the new 'blockMeshDict' file again.
08:04 In boundary, put the name of the patch as 'moving wall' . Press Enter.
08:16 Now, insert a open curly bracket and press Enter.
08:20 Now, enter the type for the moving wall , enter "type" space "wall".
08:28 Insert a semicolon and press Enter.
08:33 Now, faces, now press Enter, insert open bracket and press Enter. Press the tab key, open close bracket.
08:47 In this bracket, enter the points for faces.
08:51 Let me switch back to the slide.
08:54 Note that the order of the points should be in such a way that the thumb should be normal to the face
09:01 and fingers making a curl as shown in the figure.
09:06 The curl can be clockwise or anti-clockwise.
09:09 Also note that the points should match with the points inserted in vertices.
09:14 Now, let me switch back to the new 'blockMeshDict' file.
09:18 Now in the faces, enter 3 space 7 space 6 space 2.
09:28 Let me switch back to the slide. These are the points for the moving wall 3, 7, 6, 2.
09:35 Minimize this. Note that you can start from any point on that face. Now press Enter.
09:44 Close the bracket. Again press Enter. Close the curly bracket.
09:55 Another note: we need to enter a semi colon after you insert the points for faces. Now after the curly brackets, press Enter, again press Enter.
10:01 Now, similarly enter boundary condition and faces for the fixed walls.
10:06 Being a 2D problem the type of boundary for the front and back faces can be kept as empty.
10:13 Refer to the figure in the slide. For entering the points, minimize this.
10:19 Insert the closed brackets, put a semicolon and press Enter, again press Enter.
10:26 Now type "mergePatchPairs" and press Enter.
10:32 Since there are no patches to be merged, it can be kept empty.
10:35 Insert open close brackets. Insert a semicolon and press Enter.
10:41 We are done with creating the 'blockMeshDict' file. Save this.
10:46 The complete 'blockMeshDict' file is as shown here.
10:54 Close both the 'blockMeshDict' files.
10:56 Note that the command terminal will not work until the blockMeshDict file is closed.
11:01 Switch back to the terminal. Now, type cd space (dot) (dot) twice to return back to the 'cavity' folder. Now Mesh the geometry.
11:12 To do this, on the terminal, type: "blockMesh" and press Enter.
11:20 Now, view the geometry by typing on the command terminal paraFoam and press Enter.
11:27 This will open the ParaView window.
11:30 Now, on the left hand side, click Apply on object inspector menu. Thus, you can see the geometry.
11:39 Now, let me switch back to the slides.
11:43 In this tutorial, we learnt:
11:45 Creating a simple geometry in OpenFOAM
11:49 Viewing the geometry in Paraview .
11:52 This brings us to the end of the tutorial.
11:56 As an Assignment-
11:58 Change the dimensions of the lid driven cavity, change the grid size to 50 50 1 and view the geometry in paraView.
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13:02 This is Rahul Joshi from IIT Bombay, signing off. Thanks for joining.

Contributors and Content Editors

DeepaVedartham, Gaurav, PoojaMoolya, Pratik kamble, Sandhya.np14, Sneha