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

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(Created page with 'Tutorial: Simulating Laminar flow in a channel. Script and Narration : Rahul Joshi Keywords: Video tutorial,CFD,laminar flow,simpleFoam,channel. {| style="border-spacing:…')
 
 
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Keywords: Video tutorial,CFD,laminar flow,simpleFoam,channel.
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Keywords: Video tutorial,CFD,laminar flow,simpleFoam,channel
  
  
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|-
 
|-
 
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 1
 
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 1
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Hello and welcome to the spoken tutorial on Simulating Laminar Flow in a Channel using openfoam
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Hello and welcome to the spoken tutorial on '''Simulating 2D Laminar Flow in a Channel using openfoam'''
  
 
|-
 
|-
Line 21: Line 21:
 
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| In this tutorial I will show you  
 
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| 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 and initial boundary conditions
+
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 3 : System requirement
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| To record this tutorial I am using
  
 +
* '''Linux Operating system Ubuntu 12.04''' .
 +
*'''OpenFOAM version 2.1.1'''
 +
*'''ParaView version 3.12.0 '''
  
−
Meshing the Geometry
 
  
 +
Note that '''OpenFOAM''' version '''2.1.1''' is supported on '''Ubuntu version 12.04'''
  
−
Solving and Post Processing results in Paraview
 
  
−
 
+
Hence forth all the tutorials will be covered using '''OpenFOAM version 2.1.1''' and''' Ubuntu version 12.04'''
−
Validation with analytic result.  
+
  
 
|-
 
|-
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 3:  
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 4 : System Requirement
 +
* The tutorials were recorded using the versions specified in previous slide
  
−
System Requirement
+
* Subsequently the tutorials were edited to latest versions
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| To record this tutorial
+
  
 +
* To install latest system requirements go to Installation Sheet
  
−
I am using GNU / Linux Operating system Ubuntu 10.04 .  
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"|
  
 +
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 5 : Prerequisite
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| As a prerequisite for this tutorial, you should know how to create '''geometry''' using '''OpenFOAM.'''
  
−
OpenFOAM version 2.1.0
 
−
 
−
 
−
ParaView version 3.12.0
 
  
 +
If not, please refer to the relevant tutorials on our website.
  
 +
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 6 : About flow in a channel
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"|
 +
We '''simulate flow''' in a '''Channel''' to determine '''Flow development length''' along the downstream.
  
 +
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 7 : Channel Flow
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| '''Channel flow''' problem description.
 +
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 7 : Channel flow
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| The '''boundary names''' and '''inlet conditions''' are shown in this figure.
  
 
|-
 
|-
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 4: Prerequisite
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 8 : Boundary Conditions
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| You should know how to create geometry using OpenFOAM
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| The '''flow develpoment length''' is given by the formula
  
−
If not, please refer to the relevant tutorials on the Spoken Tutorial website
+
'''L = 0.05 * Re * D'''
  
 
|-
 
|-
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 5 : About channel flow
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 8 : Boundary Conditions
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| We simulate flow in a pipe so as to determine the flow development length along the downstream
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| '''Re''' which is the '''Reynolds number'''
−
 
+
  
  
 +
and '''D''' which is the '''channel height'''
  
 
|-
 
|-
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 6 : Diagram
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 8 : Boundary Conditions
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| The boundary names and inlet flow is shown in this figure
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Using the '''formula''' the '''length''' of the '''channel''' comes out to be '''5 meters '''
  
−
|-
 
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 7 :
 
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| The flow develpoment length is given by the formula
 
  
−
L= 0.05 * Re * D
+
and '''height''' is kept as '''1 meters'''.
  
−
The pipe is of length 5 m and height 1 m.
 
−
 
−
 
−
Inlet velocity is 1 m/s.
 
−
 
−
 
−
Reynolds number ( Re ) is 100.
 
  
 +
The '''Inlet velocity is 1''' '''meters per second'''
  
  
 +
And we are solving this for a '''Reynolds number ( Re ) equal 100'''
  
 
|-
 
|-
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Solver: simpleFoam
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 9 : File structure
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| This is a steady state problem  
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| This is a '''steady state problem '''
−
 
+
  
−
Therefore we are using a steady state incompressible solver for this case
 
  
 +
*Therefore we are using a '''steady state incompressible''' solver for this '''case'''.
 +
*This is the '''file structure''' of our '''case'''.
 +
*The '''folder''' should be created in the '''solver type''' that we choose.
 
|-
 
|-
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Demo:
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Create a '''folder''' and name it as channel in '''simpleFoam folder'''.
  
  
−
SimpleFoam in incompressible flows
+
right click >> new folder
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| We need to create a folder for our case.
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| I have already created a '''folder''' in
  
  
−
The folders should be created inside the solver type you choose.
+
'''simpleFoam folder''' of''' incompressible flow solvers'''.
  
 
|-
 
|-
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Demo
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Nmae the folder channel
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| The '''folder''' is named as''' channel'''.
  
  
−
Create a floder and name it as channel in simpleFoam folder
+
Now let me switch to the '''folder'''.
  
 +
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| copy 0,constant and system from pitzDaily to this channel folder
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Copy '''0, Constant''' and '''System folders''' of any other '''case'''.
  
−
copy 0,constant and system from pitzDaily to this channel folder
+
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"|
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| In the '''simpleFoam directory''', I have copied the''' file structure''' of '''case''' of''' pitzDaily'''.
  
 +
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"|
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Paste it in the '''channel folder'''.
  
  
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| I have already created a folder in simpleFoam folder of incompressible flow solvers
+
And make the necessary changes in the '''geometry, boundary faces''' and '''boundary condition'''.
  
−
 
+
|-
−
The folder is named as channel
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"|
−
 
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Now let me open the '''command terminal'''.
−
 
+
−
Copy 0,Constant and System folders of any other case file in simpleFoam
+
−
 
+
−
 
+
−
Here i have copied the file structure of case of pitzDaily
+
−
 
+
−
 
+
−
Paste it in the channel folder created and make the necessary changes in the geometry,boundary faces and boundary condition
+
−
 
+
−
 
+
−
We will now see the file structure
+
  
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Press Ctrl+Alt+t keys simultaneously
 
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Press Ctrl+Alt+t keys simultaneously
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| To do this press '''Ctrl+Alt +t''' keys simultaneously on your '''keyboard'''.
  
 +
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| run and press enter
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| In the '''terminal''', type '''run''' and press '''Enter'''.
  
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Type in command terminal
+
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"|
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Now type '''cd space tutorials''' and press '''Enter'''.
  
 +
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| incompressible and press enter
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Now type '''cd space incompressible''' and press '''Enter'''.
  
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run and press enter
+
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| simpleFoam and press enter
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Type '''cd space simpleFoam''' and press '''Enter'''.
  
 +
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| channel and press enter
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Now type '''cd space channel''' and press '''Enter'''.
  
−
tutorial and press enter
+
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| ls and press enter
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Now type '''ls''' and press '''Enter'''.
  
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+
|-
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incompresible and press enter
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| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"|
−
 
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| You will see three '''folders 0 , Constant and System'''
−
 
+
−
simpleFoam and press enter
+
−
 
+
−
 
+
−
channel and press enter
+
−
 
+
−
 
+
−
ls and press enter
+
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Open a command terminal by pressing Ctrl+Alt +t keys simultaneously on your keyboard.
+
−
 
+
−
 
+
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In the command terminal type the path for channel case
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−
 
+
−
 
+
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Type '''run and press enter'''
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−
 
+
−
 
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−
type '''tutorials and press enter'''
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−
 
+
−
 
+
−
type '''incompressible and press enter'''
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−
 
+
−
 
+
−
type '''simpleFoam and press enter'''
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−
 
+
−
 
+
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type '''channel and press enter'''
+
−
 
+
−
 
+
−
now type '''ls and press enter'''
+
  
 
|-
 
|-
Line 180: Line 175:
  
 
cd constant and press enter
 
cd constant and press enter
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Now type '''cd space constant''' and press '''Enter'''.
  
 +
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| ls and press enter
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Now type '''ls''' and press '''Enter'''.
  
−
ls and press enter
+
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| polymesh folder and 2 other files
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| In this you will see '''files''' containing '''properties of fluid''' and a''' folder''' named '''polymesh'''.
  
 +
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| gedit RASProperties and press enter
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| '''RASProperties''' contains '''Reynolds-averaged stress model'''.
  
−
polymesh folder and 2 other files
+
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Transportproperties
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| '''transportProperties''' contain the '''transport model'''.
  
  
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gedit RASProperties and press enter
+
And '''kinematic viscosity''' (that is '''nu'''), in this '''case''', is set at '''0.001 m²/s (meter square per second)'''.
  
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gedit transportProperties and press enter
+
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| cd polyMesh and press enter
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Now in the '''terminal''' type '''cd polyMesh''' and press '''Enter'''.
  
 +
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| ls and press enter
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Now type '''ls''' and press '''Enter'''.
  
−
In terminal type
+
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"|
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| You will see the '''blockMeshDict''' file here.
  
−
cd polyMesh and press enter
+
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| gedit blockMeshDict and press enter
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| To open the '''blockMeshDict''' file in the '''terminal '''type '''gedit blockMeshDict and press '''Enter'''.
  
  
−
in terminal type:
+
Scroll down.
  
−
gedit blockMeshDict and press enter
+
|-
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| In this you will see three folders '''0 , Constant and System'''
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| In the blockMeshDict file covertTometers is set to 1
  
  
−
type cd '''constant and press enter'''
+
Set the vertices for channel
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| The '''geometry''' is in '''meters '''so the '''convertTometers''' is set to 1.
  
  
−
type '''ls and press enter'''
+
Next we have defined the '''vertices of the channel'''.
  
 +
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Mesh size for channel
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| We have used a '''100 X 100 mesh size''' here and '''cell spacing''' is kept as '''( 1 1 1 )'''.
  
−
in this you will see files containing properties of fluid and a folder named polymesh
+
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Boundary conditions and types
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Next we have set up '''boundary conditions''' and their '''types''' which are '''inlet ,outlet,top''' and '''bottom'''.
  
 +
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| FrontAndBack boundary type as empty
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| As this is a '''2D geometry, frontAndBack''' is kept as '''empty'''.
  
−
RASProperties containes Reynolds-averaged stress model
+
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Due to a 2 dimensional geometry
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Also this being a '''simple geometry, mergePatchPair''' and '''edges''' are to be kept '''empty'''.
  
  
−
transportProperties contains transport model and
+
Close the '''blockMeshDict''' file.
  
 +
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Terminal window
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| In the '''command terminal''' type '''cd space ..(dot dot) '''and press '''Enter'''.
  
−
value of kinematic viscosity (nu) set at 0.001 m²/s.
+
|-
−
 
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Terminal window
−
 
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Again type '''cd space .. (dot dot)''' and press '''Enter'''.
−
Now type '''cd polyMesh and press enter'''
+
−
 
+
−
This contains the file blockMeshDict
+
−
 
+
−
 
+
−
To open the blockMeshDict file in the terminal '''type gedit blockMeshDict and press enter'''
+
  
 
|-
 
|-
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Refer to earlier tutorial for creating simple geometry in OpenFOAM
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| In the '''terminal''' type '''cd 0'''
−
 
+
−
 
+
−
in terminal cd space .. twice and press enter
+
−
 
+
−
In terminal type:
+
−
 
+
−
cd space 0 and press enter
+
  
  
 
type ls and press enter
 
type ls and press enter
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| To set up the blockMeshDict file refer to the tutorial for creating simple Geometry in OpenFOAM.
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Now in the '''terminal''' type '''cd space 0 (Zero)''' and press '''Enter'''.
  
  
−
The geomery is in meters so the convertTometers is set to 1
+
Now type''' ls''' and press '''Enter'''.
  
 +
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| In terminal you can see these slides
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| This contains the '''initial boundary conditions ''' and''' wall functions''' for the '''channel case'''.
  
−
next we have defined the vertices of the pipe
+
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Wall functions : epsilon, k, nut, nutilda
  
  
−
we have used a 40 X 40 mesh size here and cell spacing of
+
initial flow conditions: p, R and U
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| It should contain various files such as '''epsilon ,k, nut,nuTilda ''' which are the '''wall functions'''.
  
−
( 1 1 1 )
 
  
 +
And '''p , R''' and capital '''U''' which the are '''initial conditions of the flow'''.
  
−
next we have the boundary conditions and their types which are set as '''inlet ,outlet,top,bottom '''
+
Now let me switch back to the slides.
  
 +
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 10 : Calculate K.
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| '''Calculate k''' which is the '''turbulent kinetic energy''' from the formula given in the slide.
  
−
Since it is a 2D problem frontAndBack is kept empty.
 
  
 +
Where '''Ux, Uy and Uz''' are the '''velocity''' components in the '''x, y''' and '''z direction'''.
  
−
We have entered here the type of boundary and their faces
 
  
−
 
+
And '''U' ( dash ) = 0.05''' times '''u''' actual.
−
Arcs and mergePatch pair is kept empty.
+
−
 
+
−
 
+
−
Close the blockMeshDict file
+
−
 
+
−
 
+
−
Type cd ..(dot dot and press enter after each) twice to go back to the channel folder
+
−
 
+
−
 
+
−
Now type '''cd 0 (Time directory) and press enter'''
+
−
 
+
−
 
+
−
Type''' ls and press enter'''
+
  
 
|-
 
|-
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| In the terminal you can see the files
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 11 : Calculate epsilon
  
  
−
Slide 7 : formula to calculate epsilon and k.
+
epsilon - rate of disspiation turbulent kinetic energy
  
  
−
Do not chnge the values of nu,nuTilde and R
+
C mu - constant
  
−
Change only the boundary names
 
  
 +
l – length of channel
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Calculate '''epsilon''' from the '''formula''' given:
  
−
in terminal type : cd .. and press enter
 
  
−
System folder is kept default
+
Where '''epsilon''' is the''' rate of disspiation turbulent kinetic energy'''.
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| This contains the intial boundary conditions and wall functions for the channel case
+
  
  
−
It should contain various files named epsilon ,k, nu ,nuTilda which are the wall functions and  
+
'''C mu''' is a '''constant''' and its value is''' 0.09'''
  
  
−
p , R and U are initial conditions of the flow
+
And''' l''' is the '''length of the channel'''.
  
  
−
Calculate epsilon and k from the formula given in the
+
Let me minimise this.
  
−
figure and enter it in the file.
+
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Change only the boundary names
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Change only the '''boundary names''' in each of the above files.
  
 +
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Do not chnge the values of nu,nuTilde and R
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Note that the values of '''nut, nuTilda''' and '''R ''' are kept to be default.
  
−
Change only the boundary names in each of the above folder.
+
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"|
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Rest of the files should contain '''initial value''' for each of the '''boundary faces'''.
  
 +
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| In the terminal window type '''cd ..''' and press enter
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Now in the '''terminal''' type '''cd (space) ..(dot dot)''' and press '''Enter'''.
  
−
Note that the values in nu,nuTilde and R are to kept default
+
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| No change in system folder
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| There are no changes to be done in the '''system folder'''.
  
 +
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Mesh the geometry
  
−
Changes are only made in boundary condition names.
 
  
 +
terminal window type : blockMesh
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Now, we need to '''mesh the geometry'''.
  
−
Rest of the files should contain initial value for each of the boundary faces.
 
  
−
Now Type '''cd (space) ..(dot dot) and press enter'''
+
To do this, in the '''command terminal''' type '''blockMesh''' and press '''Enter'''.
  
  
−
There is no change in the system folder
+
The '''Meshing''' is done.
  
  
−
We need to mesh the geometry
+
Let me switch back to the slide.
  
 
|-
 
|-
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| In terminal type:blockMesh and press enter
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 12 : Solver
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| In the command terminal '''type blockMesh and press enter'''
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| The '''type of solver''' we are using here is '''simpleFoam'''.
  
−
Meshing is done
 
  
−
|-
+
It is a '''Steady-state solver''' for '''incompressible''' and '''turbulent flows'''.
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 7 :simpleFoam
+
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| The type of solver we are using here is simpleFoam
+
  
  
−
It is a Steady-state solver for incompressible, turbulent flow
+
Let me minimise this.
  
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Type simpleFoam and press enter
 
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Type simpleFoam and press enter
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| In the '''command terminal''' type '''simpleFoam''' and press '''Enter'''.
  
 +
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Iterations in terminal window
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| '''Iterations''' running will be seen in the '''command terminal'''.
  
 +
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"|
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| '''Iterations '''running may take some time.
  
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| In the command terminal '''type simpleFoam and Press enter'''
+
|-
−
 
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Iterations converge or stop at end of time step
−
 
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| The '''iterations''' will stop once the '''solution''' is '''converged''' or it reaches its '''end time value'''.
−
Iterations running will be seen in the terminal.
+
−
 
+
−
 
+
−
The iterations will stop once the solution is converged or it reaches end time value.
+
  
 
|-
 
|-
Line 356: Line 379:
  
 
type: paraFoam and press enter  
 
type: paraFoam and press enter  
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| To view the results in paraview in the terminal  
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| To view the results in '''ParaView''' in the '''terminal,''' type '''paraFoam and press '''Enter'''.
  
  
−
type '''paraFoam and press enter'''
+
This will open up the '''ParaView''' window.
−
 
+
−
 
+
−
This will open up the paraviw window
+
  
 
|-
 
|-
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Demo
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| In paraview window
  
  
−
Solid color to U
+
View the geometry
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| On left hand side of the '''ParaView''' window click '''Apply'''.
  
  
−
initial state at inlet boundary
+
The '''geometry '''can be seen here.
  
 +
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Change from solid color to U
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| On top of '''active variable control menu''' change the drop-down menu from '''solid color''' to capital '''U'''.
  
−
click on the play button
+
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Look at left side of the channel geometry
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| You can see the '''initial state''' of '''velocity magnitude''' at '''inlet.'''
  
 +
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| VCR control click PLAY button
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| On top of the '''ParaView''' window, click on the '''play''' button of the '''VCR control'''.
  
−
final contour of velocity
 
  
 +
You can see the final value of the '''velocity magnitude'''.
  
−
toggle color legend on from left hand side top
+
|-
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| On let hand side of the paraview window click Apply
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Color legend from top left
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Also toggle on the '''color legend''' from the left hand side top of the '''active variable control menu'''.
  
  
−
The geometry can be seen here.
+
Click '''Apply''' again.
  
 +
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| In object inspector menu
  
−
In top of active variable control menu change the drop down menu from solid color to capital U.
 
  
 +
click on rescale to data
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Now go to '''Display'''.
  
−
You can see the initial state of velocity magnitude at inlet.
 
  
 +
Scroll down. You can see '''Rescale''', click on it.
  
−
On top of the paraview window click on the play button of VCR control menu
+
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Check the color legend for this
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| We can see that once the '''flow''' has fully developed, it attains a '''maximum uniform velocity''' at the '''center'''.
  
  
−
you can see the final value of velocity magnitude.
+
Now let me switch back to the slides.
  
 +
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 13 :Validation
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| The results obtained can be '''validated '''with the '''analytical solution''' for '''laminar flow''' in a
 +
'''channel''' which is '''u(max)=1.5 Uavg'''
  
−
Also toggle on the color legend from left hand side top of active variable control menu.
 
  
 +
Using '''OpenFOAM''' we obtain a result of '''u(max)''' equal to '''1.48 meters per second''' which is a good match.
  
  
 +
This brings us to the end of the tutorial.
  
 
|-
 
|-
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Demo
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 14 : Summary
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| We can see that once the flow has fully devloped it attains a maximum uniform velocity at center.
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| In this tutorial we learnt
 +
 
 +
*The '''file structure of channel'''
 +
*Obtained '''solution''' using '''steady state solver'''
 +
*Viewed the '''geometry''' in '''ParaView '''
 +
*'''Validation''' with '''analytic results'''
  
 
|-
 
|-
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 8:Validation
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 15 :
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| The results obtained can be validated with the analytical solution for laminar flow in a pipe which is u(max)=1.5 Uavg
+
  
 +
Assignment
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| As an assignment:
  
−
Using openfoam we obatain a velocity of 1.48 m/s which is a good match.
+
*Solve the problem for '''Reynold Number 1500''' and
 +
*'''Validate''' it with the '''analytical result'''
  
 
|-
 
|-
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 9 : Summary
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 16 : About the Spoken Tutorial Project
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| In this tutorial we learnt
+
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Watch the video available at this URL.
  
 +
It summarizes the Spoken Tutorial project.
  
−
File structure of channel
+
If you do not have good bandwidth, you can download and watch it.
  
 +
|-
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 17 : Spoken Tutorial Workshops
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| The Spoken Tutorial Project Team
  
−
Obtained solution using steady state solver
+
-Conducts workshops using spoken tutorials
  
 +
-Gives certificates to those who pass an online test
  
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Viewed the geometry in paraview
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-For more details, please write to [mailto:contact@spoken-tutorial.org contact@spoken-tutorial.org]
  
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| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 18 :
  
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Validation with analytic results
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Forum to answer questions
 +
* Do you have questions on THIS Spoken Tutorial?
 +
* Choose the minute and second where you have the question
 +
* Explain your question briefly
 +
* Someone from the FOSSEE team will answer them. Please visit
 +
http://forums.spoken-tutorial.org/
 +
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"|
  
 
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| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 10 :
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| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 19:  
  
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Assignment
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Forum to answer questions
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* Questions not related to the Spoken Tutorial?
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* Do you have general/technical questions on the Software?
−
 
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* Please visit the FOSSEE forum
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| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| As an assignment:
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http://forums.fossee.in/
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* Choose the Software and post your question
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Solve the problem for Reynold Number 1500 and validate it with the analytical result
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| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"|  
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this brings us to the end of the tutorial
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| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 11 :
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| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 20:  
  
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Lab Migration Project
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* We coordinate migration from commercial CFD software like ANSYS to OpenFOAM
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| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| The video available at this URL:
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* We conduct free Workshops and provide solutions to CFD Problem Statements in OpenFOAM
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For more details visit this site:
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http://spoken-tutorial.org/What_is_a_Spoken_Tutorial
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http://cfd.fossee.in/
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| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"|  
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It summarizes the Spoken Tutorial project.
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If you do not have good bandwidth, you can download and watch it.
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| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 12 :
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| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 21:  
  
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About Spoken tutorials
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Case Study Project
−
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| The Spoken Tutorial Project Team
+
* We invite students to solve a feasible CFD problem statement of reasonable complexity using OpenFOAM
−
 
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* We give honorarium and certificate to those who do this
−
-Conducts workshops using spoken tutorials
+
For more details visit this site:
−
 
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http://cfd.fossee.in/
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-Gives certificates to those who pass an online test
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| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"|
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-For more details, please write to contact@spoken-tutorial.org
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| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 13
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Acknowledgement
 
Acknowledgement
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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.  
  
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This project is coordinated by http://spoken-tutorial
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More information on the same is available at the following URL http://spoken-tutorial.org/NMEICT-Intro
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More information on the same is available at the following URL link http://spoken-tutorial.org/NMEICT-Intro
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| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| About the contributor
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About the contributor
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| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| This is Rahul Joshi from IIT BOMBAY signing off.
 
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| This is Rahul Joshi from IIT BOMBAY signing off.
  
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Thanks for joining.
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Thanks for joining
  
 
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Latest revision as of 07:44, 13 June 2019

Tutorial: Simulating Laminar flow in a channel.


Script and Narration : Rahul Joshi


Keywords: Video tutorial,CFD,laminar flow,simpleFoam,channel


Visual Cue
Narration
Slide 1 Hello and welcome to the spoken tutorial on Simulating 2D Laminar Flow in a Channel using openfoam
Slide 2 : Learning Objectives 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
Slide 3 : System requirement To record this tutorial I am using
  • Linux Operating system Ubuntu 12.04 .
  • OpenFOAM version 2.1.1
  • ParaView version 3.12.0


Note that OpenFOAM version 2.1.1 is supported on Ubuntu version 12.04


Hence forth all the tutorials will be covered using OpenFOAM version 2.1.1 and Ubuntu version 12.04

Slide 4 : System Requirement
  • 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
Slide 5 : Prerequisite As a prerequisite for this tutorial, you should know how to create geometry using OpenFOAM.


If not, please refer to the relevant tutorials on our website.

Slide 6 : About flow in a channel

We simulate flow in a Channel to determine Flow development length along the downstream.

Slide 7 : Channel Flow Channel flow problem description.
Slide 7 : Channel flow The boundary names and inlet conditions are shown in this figure.
Slide 8 : Boundary Conditions The flow develpoment length is given by the formula

L = 0.05 * Re * D

Slide 8 : Boundary Conditions Re which is the Reynolds number


and D which is the channel height

Slide 8 : Boundary Conditions Using the formula the length of the channel comes out to be 5 meters


and height is kept as 1 meters.


The Inlet velocity is 1 meters per second


And we are solving this for a Reynolds number ( Re ) equal 100

Slide 9 : File structure This is a steady state problem


  • Therefore we are using a steady state incompressible solver for this case.
  • This is the file structure of our case.
  • The folder should be created in the solver type that we choose.
Create a folder and name it as channel in simpleFoam folder.


right click >> new folder

I have already created a folder in


simpleFoam folder of incompressible flow solvers.

Nmae the folder channel The folder is named as channel.


Now let me switch to the folder.

copy 0,constant and system from pitzDaily to this channel folder Copy 0, Constant and System folders of any other case.
In the simpleFoam directory, I have copied the file structure of case of pitzDaily.
Paste it in the channel folder.


And make the necessary changes in the geometry, boundary faces and boundary condition.

Now let me open the command terminal.
Press Ctrl+Alt+t keys simultaneously To do this press Ctrl+Alt +t keys simultaneously on your keyboard.
run and press enter In the terminal, type run and press Enter.
Now type cd space tutorials and press Enter.
incompressible and press enter Now type cd space incompressible and press Enter.
simpleFoam and press enter Type cd space simpleFoam and press Enter.
channel and press enter Now type cd space channel and press Enter.
ls and press enter Now type ls and press Enter.
You will see three folders 0 , Constant and System
Type in command terminal

cd constant and press enter

Now type cd space constant and press Enter.
ls and press enter Now type ls and press Enter.
polymesh folder and 2 other files In this you will see files containing properties of fluid and a folder named polymesh.
gedit RASProperties and press enter RASProperties contains Reynolds-averaged stress model.
Transportproperties transportProperties contain the transport model.


And kinematic viscosity (that is nu), in this case, is set at 0.001 m²/s (meter square per second).

cd polyMesh and press enter Now in the terminal type cd polyMesh and press Enter.
ls and press enter Now type ls and press Enter.
You will see the blockMeshDict file here.
gedit blockMeshDict and press enter To open the blockMeshDict file in the terminal type gedit blockMeshDict and press Enter.


Scroll down.

In the blockMeshDict file covertTometers is set to 1


Set the vertices for channel

The geometry is in meters so the convertTometers is set to 1.


Next we have defined the vertices of the channel.

Mesh size for channel We have used a 100 X 100 mesh size here and cell spacing is kept as ( 1 1 1 ).
Boundary conditions and types Next we have set up boundary conditions and their types which are inlet ,outlet,top and bottom.
FrontAndBack boundary type as empty As this is a 2D geometry, frontAndBack is kept as empty.
Due to a 2 dimensional geometry Also this being a simple geometry, mergePatchPair and edges are to be kept empty.


Close the blockMeshDict file.

Terminal window In the command terminal type cd space ..(dot dot) and press Enter.
Terminal window Again type cd space .. (dot dot) and press Enter.
In the terminal type cd 0


type ls and press enter

Now in the terminal type cd space 0 (Zero) and press Enter.


Now type ls and press Enter.

In terminal you can see these slides This contains the initial boundary conditions and wall functions for the channel case.
Wall functions : epsilon, k, nut, nutilda


initial flow conditions: p, R and U

It should contain various files such as epsilon ,k, nut,nuTilda which are the wall functions.


And p , R and capital U which the are initial conditions of the flow.

Now let me switch back to the slides.

Slide 10 : Calculate K. Calculate k which is the turbulent kinetic energy from the formula given in the slide.


Where Ux, Uy and Uz are the velocity components in the x, y and z direction.


And U' ( dash ) = 0.05 times u actual.

Slide 11 : Calculate epsilon


epsilon - rate of disspiation turbulent kinetic energy


C mu - constant


l – length of channel

Calculate epsilon from the formula given:


Where epsilon is the rate of disspiation turbulent kinetic energy.


C mu is a constant and its value is 0.09


And l is the length of the channel.


Let me minimise this.

Change only the boundary names Change only the boundary names in each of the above files.
Do not chnge the values of nu,nuTilde and R Note that the values of nut, nuTilda and R are kept to be default.
Rest of the files should contain initial value for each of the boundary faces.
In the terminal window type cd .. and press enter Now in the terminal type cd (space) ..(dot dot) and press Enter.
No change in system folder There are no changes to be done in the system folder.
Mesh the geometry


terminal window type : blockMesh

Now, we need to mesh the geometry.


To do this, in the command terminal type blockMesh and press Enter.


The Meshing is done.


Let me switch back to the slide.

Slide 12 : Solver The type of solver we are using here is simpleFoam.


It is a Steady-state solver for incompressible and turbulent flows.


Let me minimise this.

Type simpleFoam and press enter In the command terminal type simpleFoam and press Enter.
Iterations in terminal window Iterations running will be seen in the command terminal.
Iterations running may take some time.
Iterations converge or stop at end of time step The iterations will stop once the solution is converged or it reaches its end time value.
In terminal

type: paraFoam and press enter

To view the results in ParaView in the terminal, type paraFoam and press Enter.


This will open up the ParaView window.

In paraview window


View the geometry

On left hand side of the ParaView window click Apply.


The geometry can be seen here.

Change from solid color to U On top of active variable control menu change the drop-down menu from solid color to capital U.
Look at left side of the channel geometry You can see the initial state of velocity magnitude at inlet.
VCR control click PLAY button On top of the ParaView window, click on the play button of the VCR control.


You can see the final value of the velocity magnitude.

Color legend from top left Also toggle on the color legend from the left hand side top of the active variable control menu.


Click Apply again.

In object inspector menu


click on rescale to data

Now go to Display.


Scroll down. You can see Rescale, click on it.

Check the color legend for this 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.

Slide 13 :Validation The results obtained can be validated with the analytical solution for laminar flow in a

channel which is u(max)=1.5 Uavg


Using OpenFOAM we obtain a result of u(max) equal to 1.48 meters per second which is a good match.


This brings us to the end of the tutorial.

Slide 14 : Summary In this tutorial we learnt
  • The file structure of channel
  • Obtained solution using steady state solver
  • Viewed the geometry in ParaView
  • Validation with analytic results
Slide 15 :

Assignment

As an assignment:
  • Solve the problem for Reynold Number 1500 and
  • Validate it with the analytical result
Slide 16 : About the Spoken Tutorial Project Watch the video available at this URL.

It summarizes the Spoken Tutorial project.

If you do not have good bandwidth, you can download and watch it.

Slide 17 : Spoken Tutorial Workshops 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

Slide 18 :

Forum to answer questions

  • Do you have questions on THIS Spoken Tutorial?
  • Choose the minute and second where you have the question
  • Explain your question briefly
  • Someone from the FOSSEE team will answer them. Please visit

http://forums.spoken-tutorial.org/

Slide 19:

Forum to answer questions

  • Questions not related to the Spoken Tutorial?
  • Do you have general/technical questions on the Software?
  • Please visit the FOSSEE forum

http://forums.fossee.in/

  • Choose the Software and post your question
Slide 20:

Lab Migration Project

  • We coordinate migration from commercial CFD software like ANSYS to OpenFOAM
  • We conduct free Workshops and provide solutions to CFD Problem Statements in OpenFOAM

For more details visit this site: http://cfd.fossee.in/

Slide 21:

Case Study Project

  • We invite students to solve a feasible CFD problem statement of reasonable complexity using OpenFOAM
  • We give honorarium and certificate to those who do this

For more details visit this site: http://cfd.fossee.in/

Slide 22:

Acknowledgement


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.

More information on the same is available at the following URL http://spoken-tutorial.org/NMEICT-Intro

About the contributor This is Rahul Joshi from IIT BOMBAY signing off.

Thanks for joining

Contributors and Content Editors

DeepaVedartham, Nancyvarkey, Pravin1389, Rahuljoshi

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