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

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(Created page with "One line is said twice @08:35 {|border=1 | '''Time''' | '''Narration''' |- | 00:01 | Hello and welcome to the spoken tutorial on ''' Simulating 2D Laminar Flow in a Channel u...")
 
 
(8 intermediate revisions by 3 users not shown)
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One line is said twice @08:35
 
 
{|border=1
 
{|border=1
 
| '''Time'''
 
| '''Time'''
Line 6: Line 5:
 
|-
 
|-
 
| 00:01
 
| 00:01
| Hello and welcome to the spoken tutorial on ''' Simulating 2D Laminar Flow in a Channel using openfoam'''
+
| Hello and welcome to the '''spoken tutorial''' on ''' Simulating 2D Laminar Flow in a Channel''' using '''OpenFoam'''.
  
 
|-
 
|-
 
| 00:09
 
| 00:09
| 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 '''Linux Operating system Ubuntu 12.04''' .
+
| To record this tutorial, I am using:
'''OpenFOAM version 2.1.1'''  
+
 
'''ParaView version 3.12.0 '''
+
'''Linux Operating system Ubuntu''' version 12.04. '''OpenFOAM''' version 2.1.1
 +
 
 +
'''ParaView''' version 3.12.0  
 +
 
 +
 
  
 
|-
 
|-
 
| 00:39
 
| 00:39
|Note that '''OpenFOAM''' version '''2.1.1''' is supported on '''ubuntu version 12.04'''
+
|Note that '''OpenFOAM''' version 2.1.1 is supported on '''ubuntu''' version 12.04.
  
 
|-
 
|-
 
| 00:45
 
| 00:45
|Hence forth all the tutorials will be covered using '''OpenFOAM version 2.1.1''' and''' ubuntu version 12.04'''
+
|Hence forth all the tutorials will be covered using '''OpenFOAM ''' version 2.1.1 and''' ubuntu''' version 12.04.
  
 
|-
 
|-
 
| 00:56
 
| 00:56
| As a Pre-requisite for this tutorial You should know how to create '''geometry''' using '''OpenFOAM'''
+
| 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.
  
|-
 
| 01:03
 
|If not, please refer to the '''relevant tutorials''' on our '''website'''
 
  
 
|-
 
|-
| 01:09
+
| 01:01
|we simulate flow in a channel to determine flow development length along the downstream '''Channel flow''' problem description
+
| As a prerequisite for this tutorial, you should know how to create '''geometry''' using '''OpenFOAM'''.
  
 
|-
 
|-
| 01:19
+
| 01:08
| The '''boundary names''' and the '''inlet conditions''' are shown in this figure
+
|If not, please refer to the relevant tutorials on our website.
  
 
|-
 
|-
| 01:26
+
| 01:14
| The '''flow develpoment length''' is given by the formula '''L= 0.05 * Re * D'''
+
|We simulate flow in a channel to determine flow development length along the downstream. '''Channel flow''' problem description.
  
 
|-
 
|-
| 01:32
+
| 01:24
| '''Re''' which is the '''Reynolds number''' and '''D''' which is the '''channel height'''
+
| The '''boundary''' names and the '''inlet conditions''' are shown as in this figure.
  
 
|-
 
|-
| 01:37
+
| 01:31
| Using the '''formula''' length of the channel comes out to be '''5 meters '''and '''height''' is kept as '''1 meter'''.
+
| 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'''.
  
 
|-
 
|-
| 01:45
+
| 01:42
|The '''Inlet velocity is 1''' '''meters per second''' And we are solving this for a '''Reynolds number''' '''( Re ) equal 100'''
+
| Using the formula, the length of the '''channel''' comes out to be 5 meters and height is kept as 1 meter.
  
 
|-
 
|-
| 01:53
+
| 01:50
| This is a '''steady state problem '''.Therefore we are using a '''steady state incompressible''' solver for this case
+
|The '''Inlet velocity''' is 1 meter per second. And, we are solving this for a '''Reynolds number''' ( Re ) equal to 100.
  
 
|-
 
|-
| 02:01
+
| 01:58
| 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 a '''steady state problem '''. Therefore we are using a '''steady state incompressible''' solver for this case.
  
 
|-
 
|-
| 02:18
+
| 02:06
|The '''folder''' is named as''' channel'''Now let me switch to the '''folder'''
+
| 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'''.
  
 
|-
 
|-
| 02:25
+
| 02:27
| '''Copy 0,Constant and System''' '''folders''' of any other case file in the '''simpleFoam directory'''
+
|The folder is named as ''' channel'''. Now, let me switch to the folder.
  
 
|-
 
|-
| 02:34
+
| 02:33
| I have copied the''' file structure''' of the case of''' pitzDaily'''
+
| Copy '''0, Constant''' and '''System''' folders of any other case, in the '''simpleFoam''' directory.
  
 
|-
 
|-
| 02:38
+
| 02:42
| Paste it inside the channel folder  and make the necessary changes in the '''geometry''','''boundary faces''' and '''boundary condition'''
+
| I have copied the file structure of the case ''' pitzDaily'''.
  
 
|-
 
|-
| 02:48
+
| 02:46
| Now let me '''open the command terminal'''
+
| Paste it inside the '''channel''' folder  and make the necessary changes in the '''geometry''', '''boundary faces''' and '''boundary condition'''.
  
 
|-
 
|-
| 02:51
+
| 02:56
| To do this press '''Ctrl+Alt +t''' keys simultaneously on your '''keyboard'''
+
| Now, let me open the '''command terminal'''.
  
 
|-
 
|-
| 02:57
+
| 02:59
| In the terminal Type '''run and press enter'''
+
| To do this, press '''Ctrl+Alt +t''' keys simultaneously on your keyboard.
  
 
|-
 
|-
| 03:01
+
| 03:05
| now type cd space '''tutorials and press enter'''
+
| In the terminal, type "run" and press '''Enter'''.
  
 
|-
 
|-
| 03:08
+
| 03:09
| now type cd space '''incompressible and press enter'''
+
| Now type '''cd space tutorials''' and press '''Enter'''.
  
 
|-
 
|-
| 03:15
+
| 03:16
| type cd space '''simpleFoam and press enter'''
+
| Now type '''cd space incompressible''' and press '''Enter'''.
  
 
|-
 
|-
| 03:20
+
| 03:23
| now type cd '''channel and press enter'''
+
| Type '''cd space simpleFoam''' and press '''Enter'''.
  
 
|-
 
|-
 
| 03:28
 
| 03:28
| now type '''ls and press enter'''
+
| Now type '''cd space channel''' and press '''Enter'''.
  
 
|-
 
|-
| 03:33
+
| 03:36
| You will see three folders '''0 , Constant and System'''
+
| Now, type "ls" and press '''Enter'''.
  
 
|-
 
|-
| 03:37
+
| 03:41
| now type cd '''constant and press enter'''
+
| You will see three folders '''0, Constant''' and '''system'''.
  
 
|-
 
|-
| 03:48
+
| 03:45
| now type '''ls and press enter'''
+
| Now type '''cd space constant''' and press '''Enter'''.
  
 
|-
 
|-
| 03:52
+
| 03:56
| In this you will see '''files''' containing '''properties of fluid''' and a''' folder named polymesh'''
+
| Now type "ls" and press '''Enter'''.
  
 
|-
 
|-
| 03:59
+
| 04:00
| '''RASProperties''' contains '''Reynolds-averaged stress '''model
+
| In this, you will see the files containing properties of fluid and a folder named '''polymesh'''.
  
 
|-
 
|-
|04:03
+
| 04:07
| '''transportProperties''' contain the '''transport model '''and '''kinematic viscosity that is (nu) in this case is set at 0.001 m²/s'''.
+
| '''RASProperties''' contains '''Reynolds-averaged stress model'''.
  
 
|-
 
|-
| 04:17
+
| 04:08
| Now in terminal type '''cd polyMesh and press enter'''.Now type '''ls''' and press enter
+
| '''transportProperties''' contains the '''transport model '''and '''kinematic viscosity''' that is (nu), in this case is set at 0.01 m²/s.
  
 
|-
 
|-
| 04:30
+
| 04:25
|You will see the '''blockMeshDict''' file here
+
| Now in terminal, type '''cd space polyMesh''' and press '''Enter'''. Now, type "ls" and press '''Enter'''.
  
 
|-
 
|-
| 04:33
+
| 04:38
| To open up the '''blockMeshDict''' file in the terminal '''type gedit blockMeshDict and press enter'''Scroll down
+
|You will see the '''blockMeshDict''' file here.
  
 
|-
 
|-
| 04:48
+
| 04:42
| The geomery is in '''meters '''so the '''convertTometers''' is set to 1 next we have''' defined''' the '''vertices of the channel '''
+
| To open up the '''blockMeshDict''' file, in the terminal, type "gedit space blockMeshDict" and press '''Enter'''. Scroll down.
  
 
|-
 
|-
| 04:59
+
| 04:56
| We have used a '''100 X 100''' mesh size here and '''cell spacing''' is kept as '''( 1 1 1 )'''
+
| The geometry is in meters. So, the '''convertTometers''' is set to 1. Next, we have defined the vertices of the '''channel'''.
  
 
|-
 
|-
 
| 05:07
 
| 05:07
| Next we have setup the '''boundary conditions''' and their types which are '''inlet ,outlet,top and bottom '''
+
| We have used a '''100 X 100 mesh size''' here and '''cell spacing''' is kept as '''( 1 1 1 )'''.
  
 
|-
 
|-
| 05:19
+
| 05:15
| As this is a '''2D Geometry  front And Back''' are kept as '''empty'''
+
| Next, we have setup the '''boundary conditions''' and their types which are '''inlet, outlet, top''' and '''bottom'''.
  
 
|-
 
|-
 
| 05:27
 
| 05:27
| Also this being a '''simple geometry ''' '''mergePatchPair''' and '''edges''' are to be kept '''empty'''.Close the '''blockMeshDict''' file
+
| As this is a 2D Geometry,  '''front and Back''' are kept as '''empty'''.
  
 
|-
 
|-
| 05:38
+
| 05:35
| In the '''command terminal''' Type '''cd space ..(dot dot) '''and press enter
+
| Also, this being a simple geometry,  '''mergePatchPair''' and '''edges''' are to be kept '''empty'''. Close the '''blockMeshDict''' file.
  
 
|-
 
|-
| 05:44
+
| 05:46
| Again type '''cd space .. (dot dot)''' and press enter
+
| In the command terminal, type '''cd space ..(dot dot) '''and press '''Enter'''.
  
 
|-
 
|-
| 05:49
+
| 05:52
| Now in the terminal type '''cd '''space '''0 (Zero) and press enter'''Now Type''' ls and press enter'''
+
| Again, type '''cd space .. (dot dot)''' and press '''Enter'''.
  
 
|-
 
|-
| 05:58
+
| 05:57
| This contains the '''intial boundary conditions ''' and''' wall functions''' for the '''channel case'''
+
| Now. in the terminal, type '''cd space 0 (Zero)''' and press '''Enter'''. Now, type "ls" and press '''Enter'''.
  
 
|-
 
|-
| 06:05
+
| 06:06
| It should contain various files such as '''epsilon ,k, nut,nuTilda ''' which are the '''wall functions'''and  '''p , R and capital U'''
+
| This contains the '''intial boundary conditions ''' and''' wall functions''' for the '''channel case'''.
which the are '''initial conditions of the flow'''
+
  
 
|-
 
|-
|06:20
+
| 06:12
|Let me switch back to the slides
+
| 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'''.
  
 
|-
 
|-
| 06:24
+
|06:28
| '''Calculate k''' which is the '''turbulent kinetic energy''' from the '''formula''' given in the slide
+
|Let me switch back to the slides.
  
 
|-
 
|-
| 06:29
+
| 06:31
|Where '''Ux, Uy and Uz''' are the '''velocity''' '''components in the x, y and z direction''' And '''U' ( dash ) = 0.05''' times '''u''' actual
+
| Calculate 'k' which is the '''turbulent kinetic energy''' from the formula given in the slide
  
 
|-
 
|-
| 06:43
+
| 06:37
| Calculate '''epsilon''' from the '''formula''' given Where '''epsilon''' is the''' rate of disspiation turbulent  energy''' '''C mu''' is a '''constant''' and its value is''' 0.09'''
+
|where Ux, Uy and Uz are the '''velocity''' '''components in the x, y and z directions and''' U' ( dash ) = 0.05''' times '''u''' actual.
  
 
|-
 
|-
| 06:56
+
| 06:50
|And''' l''' is the '''length of the channel''' Let me minimise this
+
| 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.
  
 
|-
 
|-
| 07:02
+
| 07:04
| Change only the '''boundary names''' in each of the above '''folder'''
+
|And 'l' is the length of the '''channel'''. Let me minimize this.
  
 
|-
 
|-
| 07:07
+
| 07:10
| Note that the values of '''nut, nuTilda and R ''' are to kept default
+
| Change only the '''boundary names''' in each of the above files.
  
 
|-
 
|-
|07:13
+
| 07:14
| Rest of the '''files''' should contain initial value for each of the '''boundary faces'''
+
| Note that the values of '''nut, nuTilda, R ''' are kept to default.
  
 
|-
 
|-
 
| 07:21
 
| 07:21
| Now in the terminal Type '''cd (space) ..(dot dot) and press enter'''
+
| Rest of the files should contain the initial value for each of the '''boundary faces'''.
  
 
|-
 
|-
| 07:27
+
| 07:28
| There are no change to be done in the '''system folder'''
+
| Now, in the terminal, type '''cd (space) ..(dot dot)''' and press '''Enter'''.
  
 
|-
 
|-
| 07:31
+
| 07:35
|Now We need to '''mesh the geometry''' To do this In the '''command terminal''' '''type blockMesh and press enter'''
+
| There are no changes to be done in the '''system''' folder.
  
 
|-
 
|-
| 07:40
+
| 07:39
|'''Meshing''' is done.Now Let me switch back to the slide
+
|Now we need to '''mesh''' the geometry. To do this, in the command terminal, type "blockMesh" and press '''Enter'''.
  
 
|-
 
|-
| 07:45
+
| 07:48
| The '''type of solver''' we are using here is '''SimpleFoam'''It is a '''Steady-state''' solver for '''incompressible, turbulent flow'''
+
| The '''Meshing''' is done. Now let me switch back to the '''slide'''.
  
 
|-
 
|-
| 07:55
+
| 07:53
|let me minimise this
+
| The type of '''solver''' we are using here is '''SimpleFoam'''. It is a '''Steady-state''' solver for in-compressible and turbulent flows.
  
 
|-
 
|-
| 07:56
+
| 08:02
| In the '''command terminal''' '''type simpleFoam and Press enter'''
+
|Let me minimize this. In the command terminal, type "simpleFoam" and press '''Enter'''.
  
 
|-
 
|-
| 08:03
+
| 08:12
| '''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
+
| 08:36
|type '''paraFoam and press enter'''.This will open up the '''paraview window'''
+
| On the left hand side of the '''paraView''' window, click '''Apply'''. The geometry can be seen here.
  
 
|-
 
|-
| 08:28
+
| 08:43
| On let hand side of the '''paraview''' '''window''' click '''Apply'''.The '''geometry '''can be seen here.
+
| On top of the '''active variable control''' menu, change the drop down menu from '''solid color''' to capital '''U'''.
 
+
|-
+
| 08:35
+
| On top of '''active variable control menu change '''the '''drop down menu''' from '''solid color to capital U'''
+
  
 
|-
 
|-
 
| 08:50
 
| 08:50
| You can see the '''initial state''' of '''velocity magnitude''' at '''inlet.'''. On top of the '''paraview window''' click on the'''play''' '''button''' of the '''VCR control'''
+
| You can see the '''initial state''' of '''velocity magnitude''' at '''inlet.'''. On top of the '''paraView''' window, click on the'''play''' button of the '''VCR control'''.
  
 
|-
 
|-
| 09:00
+
| 09:01
|you can see the final value of the '''velocity magnitude'''
+
|You can see the final value of the '''velocity magnitude'''.
  
 
|-
 
|-
 
| 09:07
 
| 09:07
| Also''' toggle on''' the '''color legend''' from the left hand side top of '''active variable control menu''''''Click APPLY''' again
+
| Also toggle on the '''color legend''' from the left hand side top of '''active variable control''' menu, click '''APPLY''' again.
  
 
|-
 
|-
| 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 obatain a '''velocity of 1.48 meters per second''' which is a good match.This brings us to the end of the tutorial
+
|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.
  
 
|-
 
|-
| 09:57
+
| 09:58
| In this tutorial we learnt The '''File structure of channel '''
+
| 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'''.
'''Obtained solution''' using '''steady state solver'''
+
  
Viewed the geometry in '''paraview ''''''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.
  
 
|-
 
|-
| 10:08
+
| 10:18
| As an assignment
+
| Watch the video available at this URL:  http://spoken-tutorial.org/What_is_a_Spoken_Tutorial
Solve the problem for '''Reynold Number 1500''' and
+
  
'''validate it with the analytical result'''
+
It summarizes the Spoken Tutorial project. If you do not have good bandwidth, you can download and watch it.
  
 
|-
 
|-
| 10:17
+
| 10:29
| 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.
+
| The Spoken Tutorial Project team: * Conducts workshops using spoken tutorials.
  
|-
+
Gives certificates to those who pass an online testFor more details, please write to: '''contact@spoken-tutorial.org'''
| 10:28
+
| 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 [mailto:contact@spoken-tutorial.org 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 the same is available at the following URL link http://spoken-tutorial.org/NMEICT-Intro
+
|More information on this mission  is available at the following URL link: 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