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-  
+
| 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'''.
−
* '''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
+
| 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.
  
 
|-
 
|-
−
| 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.
  
 
|-
 
|-
−
| 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'''.
  
 
|-
 
|-
−
| 02:48
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| 02:56
 
| Now, let me open the '''command terminal'''.
 
| Now, let me open the '''command terminal'''.
  
 
|-
 
|-
−
| 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'''.
  
 
|-
 
|-
−
| 03:08
+
| 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'''.
  
 
|-
 
|-
−
| 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'''.
  
 
|-
 
|-
−
| 03:37
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| 03:45
 
| Now type '''cd space constant''' and press '''Enter'''.
 
| Now type '''cd space constant''' and press '''Enter'''.
  
 
|-
 
|-
−
| 03:48
+
| 03:56
 
| Now type "ls" and press '''Enter'''.
 
| Now type "ls" and press '''Enter'''.
  
 
|-
 
|-
−
| 03:52
+
| 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'''.
  
 
|-
 
|-
−
| 03:59
+
| 04:07
 
| '''RASProperties''' contains '''Reynolds-averaged stress model'''.
 
| '''RASProperties''' contains '''Reynolds-averaged stress model'''.
  
 
|-
 
|-
−
|04:03
+
| 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'''.
  
 
|-
 
|-
−
| 04:30
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| 04:38
 
|You will see the '''blockMeshDict''' file here.
 
|You will see the '''blockMeshDict''' file here.
  
 
|-
 
|-
−
| 04:33
+
| 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 288: 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 296: 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

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