Difference between revisions of "OpenFOAM/C2/2D-Laminar-Flow-in-a-channel/English-timed"

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|-
 
|-
 
| 00:09
 
| 00:09
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| In this tutorial, I will show you- '''2D geometry''' of '''channel''' '''Meshing''' the '''Geometry''''''Solving''' and '''Post Processing results''' in  '''Paraview''' and '''Validation''' using '''analytic result'''.
+
| In this tutorial, I will show you- '''2D geometry''' of '''channel''' '''Meshing''' the '''Geometry''' '''Solving''' and '''Post Processing results''' in  '''Paraview''' and '''Validation''' using '''analytic result'''.
  
 
|-
 
|-
 
| 00:25
 
| 00:25
 
| To record this tutorial, I am using:
 
| To record this tutorial, I am using:
−
  '''Linux Operating system Ubuntu''' version 12.04.
+
 
−
  '''OpenFOAM''' version 2.1.1
+
'''Linux Operating system Ubuntu''' version 12.04. '''OpenFOAM''' version 2.1.1
−
  '''ParaView''' version 3.12.0  
+
 
 +
'''ParaView''' version 3.12.0  
 +
 
 +
 
  
 
|-
 
|-
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|-
 
|-
 
| 00:56
 
| 00:56
 +
| 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.
 +
 +
 +
|-
 +
| 01:01
 
| As a prerequisite for this tutorial, you should know how to create '''geometry''' using '''OpenFOAM'''.
 
| As a prerequisite for this tutorial, you should know how to create '''geometry''' using '''OpenFOAM'''.
  
 
|-
 
|-
−
| 01:03
+
| 01:08
 
|If not, please refer to the relevant tutorials on our website.
 
|If not, please refer to the relevant tutorials on our website.
  
 
|-
 
|-
−
| 01:09
+
| 01:14
−
|We simulate flow in a channel to determine flow development length along the downstream.
+
|We simulate flow in a channel to determine flow development length along the downstream. '''Channel flow''' problem description.
−
'''Channel flow''' problem description.
+
  
 
|-
 
|-
−
| 01:19
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| 01:24
 
| The '''boundary''' names and the '''inlet conditions''' are shown as in this figure.
 
| The '''boundary''' names and the '''inlet conditions''' are shown as in this figure.
  
 
|-
 
|-
−
| 01:26
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| 01:31
−
| The '''flow develpoment length''' is given by the formula '''L= 0.05 * Re * D'''.
+
| The '''flow develpoment length''' is given by the formula '''L= 0.05 times Re' that is the '''Reynolds number''' and 'D' which is the '''channel height'''.
−
 
+
−
|-
+
−
| 01:32
+
−
| 'Re' which is the '''Reynolds number''' and 'D' which is the '''channel height'''.
+
  
 
|-
 
|-
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| 01:37
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| 01:42
 
| Using the formula, the length of the '''channel''' comes out to be 5 meters and height is kept as 1 meter.
 
| Using the formula, the length of the '''channel''' comes out to be 5 meters and height is kept as 1 meter.
  
 
|-
 
|-
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| 01:45
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| 01:50
 
|The '''Inlet velocity''' is 1 meter per second. And, we are solving this for a '''Reynolds number''' ( Re ) equal to 100.
 
|The '''Inlet velocity''' is 1 meter per second. And, we are solving this for a '''Reynolds number''' ( Re ) equal to 100.
  
 
|-
 
|-
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| 01:53
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| 01:58
 
| This is a '''steady state problem '''. Therefore we are using a '''steady state incompressible''' solver for this case.
 
| This is a '''steady state problem '''. Therefore we are using a '''steady state incompressible''' solver for this case.
  
 
|-
 
|-
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| 02:01
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| 02:06
 
| This is the file structure of our case. The folder should be created in the '''solver''' type that we choose. I have already created a folder in '''simpleFoam''' folder of''' incompressible flow solvers'''.
 
| This is the file structure of our case. The folder should be created in the '''solver''' type that we choose. I have already created a folder in '''simpleFoam''' folder of''' incompressible flow solvers'''.
  
 
|-
 
|-
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| 02:18
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| 02:27
 
|The folder is named as ''' channel'''. Now, let me switch to the folder.
 
|The folder is named as ''' channel'''. Now, let me switch to the folder.
  
 
|-
 
|-
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| 02:25
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| 02:33
 
| Copy '''0, Constant''' and '''System''' folders of any other case, in the '''simpleFoam''' directory.
 
| Copy '''0, Constant''' and '''System''' folders of any other case, in the '''simpleFoam''' directory.
  
 
|-
 
|-
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| 02:34
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| 02:42
 
| I have copied the file structure of the case ''' pitzDaily'''.
 
| I have copied the file structure of the case ''' pitzDaily'''.
  
 
|-
 
|-
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| 02:38
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| 02:46
 
| Paste it inside the '''channel''' folder  and make the necessary changes in the '''geometry''', '''boundary faces''' and '''boundary condition'''.
 
| Paste it inside the '''channel''' folder  and make the necessary changes in the '''geometry''', '''boundary faces''' and '''boundary condition'''.
  
 
|-
 
|-
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| 02:48
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| 02:56
 
| Now, let me open the '''command terminal'''.
 
| Now, let me open the '''command terminal'''.
  
 
|-
 
|-
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| 02:51
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| 02:59
 
| To do this, press '''Ctrl+Alt +t''' keys simultaneously on your keyboard.
 
| To do this, press '''Ctrl+Alt +t''' keys simultaneously on your keyboard.
  
 
|-
 
|-
−
| 02:57
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| 03:05
 
| In the terminal, type "run" and press '''Enter'''.
 
| In the terminal, type "run" and press '''Enter'''.
  
 
|-
 
|-
−
| 03:01
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| 03:09
 
| Now type '''cd space tutorials''' and press '''Enter'''.
 
| Now type '''cd space tutorials''' and press '''Enter'''.
  
 
|-
 
|-
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| 03:08
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| 03:16
 
| Now type '''cd space incompressible''' and press '''Enter'''.
 
| Now type '''cd space incompressible''' and press '''Enter'''.
  
 
|-
 
|-
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| 03:15
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| 03:23
 
| Type '''cd space simpleFoam''' and press '''Enter'''.
 
| Type '''cd space simpleFoam''' and press '''Enter'''.
  
 
|-
 
|-
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| 03:20
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| 03:28
 
| Now type '''cd space channel''' and press '''Enter'''.
 
| Now type '''cd space channel''' and press '''Enter'''.
  
 
|-
 
|-
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| 03:28
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| 03:36
 
| Now, type "ls" and press '''Enter'''.
 
| Now, type "ls" and press '''Enter'''.
  
 
|-
 
|-
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| 03:33
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| 03:41
 
| You will see three folders '''0, Constant''' and '''system'''.
 
| You will see three folders '''0, Constant''' and '''system'''.
  
 
|-
 
|-
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| 03:37
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| 03:45
 
| Now type '''cd space constant''' and press '''Enter'''.
 
| Now type '''cd space constant''' and press '''Enter'''.
  
 
|-
 
|-
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| 03:48
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| 03:56
 
| Now type "ls" and press '''Enter'''.
 
| Now type "ls" and press '''Enter'''.
  
 
|-
 
|-
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| 03:52
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| 04:00
 
| In this, you will see the files containing properties of fluid and a folder named '''polymesh'''.
 
| In this, you will see the files containing properties of fluid and a folder named '''polymesh'''.
  
 
|-
 
|-
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| 03:59
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| 04:07
 
| '''RASProperties''' contains '''Reynolds-averaged stress model'''.
 
| '''RASProperties''' contains '''Reynolds-averaged stress model'''.
  
 
|-
 
|-
−
|04:03
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| 04:08
 
| '''transportProperties''' contains the '''transport model '''and '''kinematic viscosity''' that is (nu), in this case is set at 0.01 m²/s.
 
| '''transportProperties''' contains the '''transport model '''and '''kinematic viscosity''' that is (nu), in this case is set at 0.01 m²/s.
  
 
|-
 
|-
−
| 04:17
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| 04:25
 
| Now in terminal, type '''cd space polyMesh''' and press '''Enter'''. Now, type "ls" and press '''Enter'''.
 
| Now in terminal, type '''cd space polyMesh''' and press '''Enter'''. Now, type "ls" and press '''Enter'''.
  
 
|-
 
|-
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| 04:30
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| 04:38
 
|You will see the '''blockMeshDict''' file here.
 
|You will see the '''blockMeshDict''' file here.
  
 
|-
 
|-
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| 04:33
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| 04:42
 
| To open up the '''blockMeshDict''' file, in the terminal, type "gedit space blockMeshDict" and press '''Enter'''. Scroll down.
 
| To open up the '''blockMeshDict''' file, in the terminal, type "gedit space blockMeshDict" and press '''Enter'''. Scroll down.
  
 
|-
 
|-
−
| 04:48
+
| 04:56
 
| The geometry is in meters. So, the '''convertTometers''' is set to 1. Next, we have defined the vertices of the '''channel'''.  
 
| The geometry is in meters. So, the '''convertTometers''' is set to 1. Next, we have defined the vertices of the '''channel'''.  
  
 
|-
 
|-
−
| 04:59
+
| 05:07
 
| We have used a '''100 X 100 mesh size''' here and '''cell spacing''' is kept as '''( 1 1 1 )'''.
 
| We have used a '''100 X 100 mesh size''' here and '''cell spacing''' is kept as '''( 1 1 1 )'''.
  
 
|-
 
|-
−
| 05:07
+
| 05:15
 
| Next, we have setup the '''boundary conditions''' and their types which are '''inlet, outlet, top''' and '''bottom'''.
 
| Next, we have setup the '''boundary conditions''' and their types which are '''inlet, outlet, top''' and '''bottom'''.
  
 
|-
 
|-
−
| 05:19
+
| 05:27
 
| As this is a 2D Geometry,  '''front and Back''' are  kept as '''empty'''.
 
| As this is a 2D Geometry,  '''front and Back''' are  kept as '''empty'''.
  
 
|-
 
|-
−
| 05:27
+
| 05:35
 
| Also, this being a simple geometry,  '''mergePatchPair''' and '''edges''' are to be kept '''empty'''. Close the '''blockMeshDict''' file.  
 
| Also, this being a simple geometry,  '''mergePatchPair''' and '''edges''' are to be kept '''empty'''. Close the '''blockMeshDict''' file.  
  
 
|-
 
|-
−
| 05:38
+
| 05:46
 
| In the command terminal, type '''cd space ..(dot dot) '''and press '''Enter'''.  
 
| In the command terminal, type '''cd space ..(dot dot) '''and press '''Enter'''.  
  
 
|-
 
|-
−
| 05:44
+
| 05:52
 
| Again, type '''cd space .. (dot dot)''' and press '''Enter'''.
 
| Again, type '''cd space .. (dot dot)''' and press '''Enter'''.
  
 
|-
 
|-
−
| 05:49
+
| 05:57
 
| Now. in the terminal, type '''cd space 0 (Zero)''' and press '''Enter'''. Now, type "ls" and press '''Enter'''.
 
| Now. in the terminal, type '''cd space 0 (Zero)''' and press '''Enter'''. Now, type "ls" and press '''Enter'''.
  
 
|-
 
|-
−
| 05:58
+
| 06:06
 
| This contains the '''intial boundary conditions ''' and''' wall functions''' for the '''channel case'''.
 
| This contains the '''intial boundary conditions ''' and''' wall functions''' for the '''channel case'''.
  
 
|-
 
|-
−
| 06:05
+
| 06:12
 
| It should contain various files such as '''epsilon, k, nut, nuTilda ''' which are the '''wall functions'''and  'p' , 'R' and capital 'U' which  are '''initial conditions''' of the '''flow'''.
 
| It should contain various files such as '''epsilon, k, nut, nuTilda ''' which are the '''wall functions'''and  'p' , 'R' and capital 'U' which  are '''initial conditions''' of the '''flow'''.
  
 
|-
 
|-
−
|06:20
+
|06:28
 
|Let me switch back to the slides.
 
|Let me switch back to the slides.
  
 
|-
 
|-
−
| 06:24
+
| 06:31
 
| Calculate 'k' which is the '''turbulent kinetic energy''' from the formula given in the slide
 
| Calculate 'k' which is the '''turbulent kinetic energy''' from the formula given in the slide
  
 
|-
 
|-
−
| 06:29
+
| 06:37
 
|where Ux, Uy and Uz are the '''velocity''' '''components in the x, y and z directions and''' U' ( dash ) = 0.05''' times '''u''' actual.
 
|where Ux, Uy and Uz are the '''velocity''' '''components in the x, y and z directions and''' U' ( dash ) = 0.05''' times '''u''' actual.
  
 
|-
 
|-
−
| 06:43
+
| 06:50
 
| Calculate '''epsilon''' from the formula given where epsilon is the''' rate of dissipation of turbulent  energy''', '''C mu''' is a '''constant''' and its value is 0.09.
 
| Calculate '''epsilon''' from the formula given where epsilon is the''' rate of dissipation of turbulent  energy''', '''C mu''' is a '''constant''' and its value is 0.09.
  
 
|-
 
|-
−
| 06:56
+
| 07:04
 
|And 'l' is the length of the '''channel'''. Let me minimize this.
 
|And 'l' is the length of the '''channel'''. Let me minimize this.
  
 
|-
 
|-
−
| 07:02
+
| 07:10
 
| Change only the '''boundary names''' in each of the above files.
 
| Change only the '''boundary names''' in each of the above files.
  
 
|-
 
|-
−
| 07:07
+
| 07:14
 
| Note that the values of '''nut, nuTilda, R ''' are kept to default.
 
| Note that the values of '''nut, nuTilda, R ''' are kept to default.
  
 
|-
 
|-
−
|07:13
+
| 07:21
 
| Rest of the files should contain the initial value for each of the '''boundary faces'''.
 
| Rest of the files should contain the initial value for each of the '''boundary faces'''.
  
 
|-
 
|-
−
| 07:21
+
| 07:28
 
| Now, in the terminal, type '''cd (space) ..(dot dot)''' and press '''Enter'''.
 
| Now, in the terminal, type '''cd (space) ..(dot dot)''' and press '''Enter'''.
  
 
|-
 
|-
−
| 07:27
+
| 07:35
 
| There are no changes to be done in the '''system''' folder.
 
| There are no changes to be done in the '''system''' folder.
  
 
|-
 
|-
−
| 07:31
+
| 07:39
 
|Now we need to '''mesh''' the geometry. To do this, in the command terminal, type "blockMesh" and press '''Enter'''.
 
|Now we need to '''mesh''' the geometry. To do this, in the command terminal, type "blockMesh" and press '''Enter'''.
  
 
|-
 
|-
−
| 07:40
+
| 07:48
 
| The '''Meshing''' is done. Now let me switch back to the '''slide'''.
 
| The '''Meshing''' is done. Now let me switch back to the '''slide'''.
  
 
|-
 
|-
−
| 07:45
+
| 07:53
 
| The type of '''solver''' we are using here is '''SimpleFoam'''. It is a '''Steady-state''' solver for in-compressible and turbulent flows.
 
| The type of '''solver''' we are using here is '''SimpleFoam'''. It is a '''Steady-state''' solver for in-compressible and turbulent flows.
  
 
|-
 
|-
−
| 07:55
+
| 08:02
−
|Let me minimize this.  
+
|Let me minimize this. In the command terminal, type "simpleFoam" and press '''Enter'''.
  
 
|-
 
|-
−
| 07:56
+
| 08:12
−
| In the command terminal, type "simpleFoam" and press '''Enter'''.
+
−
 
+
−
|-
+
−
| 08:03
+
 
| '''Iterations''' running will be seen in the command terminal.
 
| '''Iterations''' running will be seen in the command terminal.
  
 
|-
 
|-
−
| 08:07
+
| 08:15
 
| '''Iterations '''running may take some time.
 
| '''Iterations '''running may take some time.
  
 
|-
 
|-
−
| 08:11
+
| 08:18
 
| The '''iterations''' will stop once the solution is converged or it reaches its '''end time value'''.
 
| The '''iterations''' will stop once the solution is converged or it reaches its '''end time value'''.
  
 
|-
 
|-
−
| 08:16
+
| 08:24
−
| To view the results in '''paraView''', in the terminal,  
+
| To view the results in '''paraView''', in the terminal, type "paraFoam" and press '''Enter'''. This will open up the '''paraView''' window.
−
 
+
−
|-
+
−
| 08:20
+
−
|type "paraFoam" and press '''Enter'''. This will open up the '''paraView''' window.
+
  
 
|-
 
|-
−
| 08:28
+
| 08:36
 
| On the left hand side of the '''paraView''' window, click '''Apply'''. The geometry can be seen here.
 
| On the left hand side of the '''paraView''' window, click '''Apply'''. The geometry can be seen here.
  
 
|-
 
|-
−
| 08:35
+
| 08:43
 
| On top of the '''active variable control''' menu, change the drop down menu from '''solid color''' to capital '''U'''.
 
| On top of the '''active variable control''' menu, change the drop down menu from '''solid color''' to capital '''U'''.
  
Line 284: Line 279:
  
 
|-
 
|-
−
| 09:00
+
| 09:01
−
|you can see the final value of the '''velocity magnitude'''.
+
|You can see the final value of the '''velocity magnitude'''.
  
 
|-
 
|-
Line 292: Line 287:
  
 
|-
 
|-
−
| 09:16
+
| 09:17
 
| Now go to '''Display''', scroll down. You can see '''Rescale''', click on it.
 
| Now go to '''Display''', scroll down. You can see '''Rescale''', click on it.
  
 
|-
 
|-
−
| 09:24
+
| 09:25
 
| We can see that once the '''flow''' has fully developed, it attains a maximum uniform velocity at the center. Now, let me switch back to the slides.
 
| We can see that once the '''flow''' has fully developed, it attains a maximum uniform velocity at the center. Now, let me switch back to the slides.
  
 
|-
 
|-
−
| 09:36
+
| 09:37
 
| The results obtained can be validated with the analytical solution for '''laminar flow''' in a'''channel''' which is u(max)=1.5 Uavg.
 
| The results obtained can be validated with the analytical solution for '''laminar flow''' in a'''channel''' which is u(max)=1.5 Uavg.
  
 
|-
 
|-
−
| 09:46
+
| 09:47
−
|Using '''openFoam''', we obtain a result of u(max) = 1.48 meters per second which is a good match.  
+
|Using '''openFoam''', we obtain a result of u(max) = 1.48 meters per second which is a good match. This brings us to the end of the tutorial.
−
This brings us to the end of the tutorial.
+
  
 
|-
 
|-
−
| 09:57
+
| 09:58
 
| In this tutorial, we learnt the file structure of '''channel''', obtained solution using '''steady state solver'''. Viewed the geometry in '''paraview ''' and '''validation''' with '''analytic results'''.
 
| In this tutorial, we learnt the file structure of '''channel''', obtained solution using '''steady state solver'''. Viewed the geometry in '''paraview ''' and '''validation''' with '''analytic results'''.
  
 
|-
 
|-
−
| 10:08
+
| 10:09
−
| As an assignment-  
+
| As an assignment- solve the problem for '''Reynold's Number equal to 1500''' and '''validate''' it with the analytical result.
−
solve the problem for '''Reynold's Number equal to 1500''' and '''validate''' it with the analytical result.
+
  
 
|-
 
|-
−
| 10:17
+
| 10:18
−
| 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
+
 
−
  It summarizes the Spoken Tutorial project. If you do not have good bandwidth, you can download and watch it.
+
It summarizes the Spoken Tutorial project. If you do not have good bandwidth, you can download and watch it.
  
 
|-
 
|-
−
| 10:28
+
| 10:29
 
| The Spoken Tutorial Project team: * Conducts workshops using spoken tutorials.
 
| 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: '''contact@spoken-tutorial.org'''  
+
Gives certificates to those who pass an online test. For more details, please write to: '''contact@spoken-tutorial.org'''  
  
 
|-
 
|-
−
| 10:42
+
| 11:05
−
| '''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.  
+
| '''Spoken Tutorials''' is a  part of '''Talk to a Teacher''' project. It is supported by the National Mission on Education through ICT, MHRD, Government of India.  
  
 
|-
 
|-
−
| 10:52
+
| 11:15
−
|More information on this mission   is available at the following URL link:
+
|More information on this mission is available at the following URL link: http://spoken-tutorial.org/NMEICT-Intro
−
http://spoken-tutorial.org/NMEICT-Intro
+
  
 
|-
 
|-
−
| 10:57
+
| 11:20
 
| 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 15:00, 11 April 2019

Time Narration
00:01 Hello and welcome to the spoken tutorial on Simulating 2D Laminar Flow in a Channel using OpenFoam.
00:09 In this tutorial, I will show you- 2D geometry of channel Meshing the Geometry Solving and Post Processing results in Paraview and Validation using analytic result.
00:25 To record this tutorial, I am using:

Linux Operating system Ubuntu version 12.04. OpenFOAM version 2.1.1

ParaView version 3.12.0


00:39 Note that OpenFOAM version 2.1.1 is supported on ubuntu version 12.04.
00:45 Hence forth all the tutorials will be covered using OpenFOAM version 2.1.1 and ubuntu version 12.04.
00:56 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.


01:01 As a prerequisite for this tutorial, you should know how to create geometry using OpenFOAM.
01:08 If not, please refer to the relevant tutorials on our website.
01:14 We simulate flow in a channel to determine flow development length along the downstream. Channel flow problem description.
01:24 The boundary names and the inlet conditions are shown as in this figure.
01:31 The flow develpoment length is given by the formula L= 0.05 times Re' that is the Reynolds number and 'D' which is the channel height.
01:42 Using the formula, the length of the channel comes out to be 5 meters and height is kept as 1 meter.
01:50 The Inlet velocity is 1 meter per second. And, we are solving this for a Reynolds number ( Re ) equal to 100.
01:58 This is a steady state problem . Therefore we are using a steady state incompressible solver for this case.
02:06 This is the file structure of our case. The folder should be created in the solver type that we choose. I have already created a folder in simpleFoam folder of incompressible flow solvers.
02:27 The folder is named as channel. Now, let me switch to the folder.
02:33 Copy 0, Constant and System folders of any other case, in the simpleFoam directory.
02:42 I have copied the file structure of the case pitzDaily.
02:46 Paste it inside the channel folder and make the necessary changes in the geometry, boundary faces and boundary condition.
02:56 Now, let me open the command terminal.
02:59 To do this, press Ctrl+Alt +t keys simultaneously on your keyboard.
03:05 In the terminal, type "run" and press Enter.
03:09 Now type cd space tutorials and press Enter.
03:16 Now type cd space incompressible and press Enter.
03:23 Type cd space simpleFoam and press Enter.
03:28 Now type cd space channel and press Enter.
03:36 Now, type "ls" and press Enter.
03:41 You will see three folders 0, Constant and system.
03:45 Now type cd space constant and press Enter.
03:56 Now type "ls" and press Enter.
04:00 In this, you will see the files containing properties of fluid and a folder named polymesh.
04:07 RASProperties contains Reynolds-averaged stress model.
04:08 transportProperties contains the transport model and kinematic viscosity that is (nu), in this case is set at 0.01 m²/s.
04:25 Now in terminal, type cd space polyMesh and press Enter. Now, type "ls" and press Enter.
04:38 You will see the blockMeshDict file here.
04:42 To open up the blockMeshDict file, in the terminal, type "gedit space blockMeshDict" and press Enter. Scroll down.
04:56 The geometry is in meters. So, the convertTometers is set to 1. Next, we have defined the vertices of the channel.
05:07 We have used a 100 X 100 mesh size here and cell spacing is kept as ( 1 1 1 ).
05:15 Next, we have setup the boundary conditions and their types which are inlet, outlet, top and bottom.
05:27 As this is a 2D Geometry, front and Back are kept as empty.
05:35 Also, this being a simple geometry, mergePatchPair and edges are to be kept empty. Close the blockMeshDict file.
05:46 In the command terminal, type cd space ..(dot dot) and press Enter.
05:52 Again, type cd space .. (dot dot) and press Enter.
05:57 Now. in the terminal, type cd space 0 (Zero) and press Enter. Now, type "ls" and press Enter.
06:06 This contains the intial boundary conditions and wall functions for the channel case.
06:12 It should contain various files such as epsilon, k, nut, nuTilda which are the wall functionsand 'p' , 'R' and capital 'U' which are initial conditions of the flow.
06:28 Let me switch back to the slides.
06:31 Calculate 'k' which is the turbulent kinetic energy from the formula given in the slide
06:37 where Ux, Uy and Uz are the velocity components in the x, y and z directions and U' ( dash ) = 0.05 times u actual.
06:50 Calculate epsilon from the formula given where epsilon is the rate of dissipation of turbulent energy, C mu is a constant and its value is 0.09.
07:04 And 'l' is the length of the channel. Let me minimize this.
07:10 Change only the boundary names in each of the above files.
07:14 Note that the values of nut, nuTilda, R are kept to default.
07:21 Rest of the files should contain the initial value for each of the boundary faces.
07:28 Now, in the terminal, type cd (space) ..(dot dot) and press Enter.
07:35 There are no changes to be done in the system folder.
07:39 Now we need to mesh the geometry. To do this, in the command terminal, type "blockMesh" and press Enter.
07:48 The Meshing is done. Now let me switch back to the slide.
07:53 The type of solver we are using here is SimpleFoam. It is a Steady-state solver for in-compressible and turbulent flows.
08:02 Let me minimize this. In the command terminal, type "simpleFoam" and press Enter.
08:12 Iterations running will be seen in the command terminal.
08:15 Iterations running may take some time.
08:18 The iterations will stop once the solution is converged or it reaches its end time value.
08:24 To view the results in paraView, in the terminal, type "paraFoam" and press Enter. This will open up the paraView window.
08:36 On the left hand side of the paraView window, click Apply. The geometry can be seen here.
08:43 On top of the active variable control menu, change the drop down menu from solid color to capital U.
08:50 You can see the initial state of velocity magnitude at inlet.. On top of the paraView window, click on theplay button of the VCR control.
09:01 You can see the final value of the velocity magnitude.
09:07 Also toggle on the color legend from the left hand side top of active variable control menu, click APPLY again.
09:17 Now go to Display, scroll down. You can see Rescale, click on it.
09:25 We can see that once the flow has fully developed, it attains a maximum uniform velocity at the center. Now, let me switch back to the slides.
09:37 The results obtained can be validated with the analytical solution for laminar flow in achannel which is u(max)=1.5 Uavg.
09:47 Using openFoam, we obtain a result of u(max) = 1.48 meters per second which is a good match. This brings us to the end of the tutorial.
09:58 In this tutorial, we learnt the file structure of channel, obtained solution using steady state solver. Viewed the geometry in paraview and validation with analytic results.
10:09 As an assignment- solve the problem for Reynold's Number equal to 1500 and validate it with the analytical result.
10:18 Watch 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.

10:29 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: contact@spoken-tutorial.org

11:05 Spoken Tutorials is a part of Talk to a Teacher project. It is supported by the National Mission on Education through ICT, MHRD, Government of India.
11:15 More information on this mission is available at the following URL link: http://spoken-tutorial.org/NMEICT-Intro
11:20 This is Rahul Joshi from IIT Bombay, signing off. Thanks for joining.

Contributors and Content Editors

DeepaVedartham, PoojaMoolya, Pratik kamble, Sandhya.np14

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