OpenFOAM/C3/Flow-over-a-flat-plate/English
Tutorial: Flow over a flat plate using OpenFOAM.
Script and Narration: Rahul Joshi
Keywords: Video tutorial, CFD, Flat plate, Boundary layer, glyph (vector plotting).
Visual Cue | Narration |
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Slide 1 | Hello and welcome to the spoken tutorial on Flow over a flat plate using OpenFOAM. |
Slide 2 : Learning Objectives | In this tutorial I will teach you about
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Slide 3:
System Requirement |
To record this tutorial
I am using
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Slide 4:
System Requirement
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Slide 5: Flow over Flat Plate | Flow over flat plate is a fundamental problem in fluid mechanics. |
Slide 6: Flow over Flat Plate
Flow over a flat plate diagram |
We can visualise the growth of the boundary layer.
Boundary layer is a very thin region above the body where the velocity is 0.99 times the free stream velocity. |
Slide 7: Diagram of boundary conditions. | This is a diagram of the flow over the flat plate.
The boundary conditions are given as follows-
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Slide 8: Inlet parameters |
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Click on Home>> OpenFoam | Now let us go to the Home folder.
In the Home folder, click on the OpenFoam folder. |
Click on Run >> Tutorials | Then go to the Run directory.
You will see Tutorials. Click on it. |
Click on Incompressible >> SimpleFoam | Scroll down and then click on Incompressible.
Scroll down. You will see the simpleFoam folder, click on it. This solver suits our case. |
Right click >> Create new folder >> flatplate | In this, create a folder by the name flatplate
Right click Create New Folder flatplate |
Double-click pitzdaily folder. | Now, let us open the pitzdaily case. |
Zoom in | Let me zoom this. |
Select 0,constant and system folders | Copy the three folders 0, constant and system. |
Ctrl + C. | Copy this. |
Go back to SimpleFoam >> flatplate folder.
Paste them there. |
Now let us go one level back.
Paste these three folders inside the flatplate folder. |
Click on constant >> polyMesh | Open the constant folder and then the polyMesh folder. |
Change the geometry and boundary condition names in the blockMeshDict file. | |
Open blockMeshDict file >> Scroll down. | I have already made the changes.
Let us open the blockMeshDict file. Scroll down. The geometry is in meters. |
We have set the dimensions of the flatplate. | |
Simplegrading (1 3 1) | You can see the simpleGrading.
It is kept as (1 3 1) as we need a finer mesh near the plate. |
Go two levels back | Now close this.
Go two levels back. |
Make changes in the boundary condition | Similarly, make changes in the boundary condition names inside the files in the 0 folder.
These files have pressure, velocity and wall functions. |
Go one level back. | To calculate the values of wall functions, please refer to the earlier tutorials in the OpenFoam series.
Let us go one level back. |
The system folder can be kept default.
Let us close this. | |
Let us open the terminal window :
Press Ctrl+Alt+t keys simultaneously |
Now let us open the terminal window.
In the terminal window, type run and press Enter. |
Type cd tutorials | Now type cd space tutorials press' Enter. |
Type cd incompressible | Now type cd incompressible press Enter. |
Type cd simpleFoam | Now type cd space simpleFoam press Enter. |
Type ls | Now type ls and press Enter. |
We can see the flatplate folder. | |
Type cd flatplate | Now type cd space flatplate and press Enter. |
Type ls | Now type ls and press Enter. |
You can see the three folders 0, constant and system. | |
Type blockMesh | Now, we will mesh the geometry.
We are using a course mesh for this problem. Meshing can be done by typing blockMesh in the terminal. |
Press Enter.
Meshing has been done. | |
Note that if there is some error in the blockMesh file.
it will be shown in the terminal window. | |
Type paraFoam | To view the geometry, type paraFoam and press Enter. |
Paraview window >> click on APPLY button | After the ParaView window opens, on the left hand side of the object inspector menu, click Apply.
We can see the geometry. |
Close the ParaView window. | Close the ParaView window.
Let me switch back to the slides. |
Slide 9: solver | The solver we are using here is simpleFoam
SimpleFoam is a steady state solver for *incompressible
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Demo :
type simpleFoam |
Let me switch back to the terminal window.
In the terminal window, type simpleFoam and press Enter.
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Type paraFoam | Once the solving is done, type paraFoam to view the results. |
In the Paraview window click on APPLY button on left hand side | On the left hand side of the Object Inspector menu, click Apply to view the geometry. |
Properties | Scroll down the properties panel of the Object Inspector menu for time step, regions and fields. |
Change the drop down menu from Solid Color to U | To view the contours from the drop down menu,
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You can see the initial condition of the velocity. | |
VCR control | Now on top of the ParaView window, you will see the VCR control. |
Click on Play button of VCR control | Click on the Play button. |
You will see the contour of Pressure or Velocity on the flat plate accordingly. | |
Toggle on the Color legend | This is the velocity contour.
Toggle on the Color legend. |
Color legend left hand side top icon | To do this, click on the color legend icon on the Active Variable Control menu. |
Click on APPLY button | Click Apply in the Object inspector menu. |
Click on Display | In the Object inspector menu, click on Display. |
Click on rescale to data range | Scroll down and click on Rescale to data range. |
Shift color legend on top of the geometry | Let me shift this Color legend on top. |
Top menu >> Filter > Common > glyph | To visualize the Vector Plot,
go to the Filters Menu > Common > glyph |
Go to Properties | Go to the Properties in Object Inspector menu. |
Click Apply | Click Apply on the left hand side of Object Inspector menu. |
Changing vector size | You can change the number of vectors by changing their size at the bottom. |
Scroll down and click on Edit button
set scale factor 0.1 |
Also, the size of the vectors can be changed by clicking on the Edit button.
The set scale factor can be changed to 0.1 |
Click the Apply button | Again, click the Apply button. |
Now let me zoom this. | |
Click on ZoomToBox icon | To do this, in the Active Variable Control menu, click on the zoomToBox option. |
And zoom over any area that you desire. | |
Parabolic variation of vector plot | We can see the parabolic variation of vector plots as the flow moves over the plate. |
Delete the vector plot | Delete this. Now delete the vector plot. |
Corresponding to color of 1 in color legend | Also, we can see that the color near to 1 corresponds to the velocity of 0.99 times the free stream velocity. |
To plot the data along x and y axis | We can also plot the variation of velocity along the x and y axes using the plot data over line. |
Slide 10: Summary | This brings us to the end of the tutorial.
In this tutorial we learnt :
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Slide 11: Assignment | As an assignment,
Create a geometry of flow over the flat plate. Refine the grid spacing near the plate. |
Slide 12 : About Spoken tutorials |
http://spoken-tutorial.org/What_is_a_Spoken_Tutorial
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Slide 13: Spoken Tutorial Worekshops | 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 at the rate spoken hyphen tutorial dot org |
Slide 14: Forum to answer questions
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Slide 15: Forum to answer questions
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Slide 16: Lab Migration Project
For more details visit this site: http://cfd.fossee.in/ |
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Slide 17: Case Study Project
For more details visit this site: http://cfd.fossee.in/ |
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Slide 18:
Acknowledgement
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Spoken Tutorial project is a part of the Talk to a Teacher project,
It is supported by the National Mission on Education through ICT, MHRD, Government of India More information on this mission is available at this URL http://spoken-tutorial.org/NMEICT-Intro |
About the contributor | This is Rahul Joshi from IIT BOMBAY signing off
Thanks for joining |