Difference between revisions of "OpenFOAM/C3/Flow-over-a-flat-plate/English"
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| In this tutorial I will teach you about the | | In this tutorial I will teach you about the | ||
| − | *Geometry of the flat plate | + | * Geometry of the flat plate |
| − | * | + | * Changing the grid spacing in '''meshing''' |
| − | * Post | + | * Post Processing results in '''ParaView''' and |
| − | * | + | * Visualising using '''Vector Plot'''. |
|- | |- | ||
| Line 55: | Line 55: | ||
*You have the '''Inlet''' | *You have the '''Inlet''' | ||
| − | *'''Plate''' | + | *the '''Plate''' |
*'''Top''' – which is the '''Farfield''' | *'''Top''' – which is the '''Farfield''' | ||
| − | *and '''Outlet''' | + | *and '''Outlet''' – which is the''' pressure outlet boundary''' |
Free stream velocity '''U = 1 m/s''', and | Free stream velocity '''U = 1 m/s''', and | ||
| − | + | we are solving this for '''Reynolds no (Re) = 100''' | |
|- | |- | ||
Revision as of 12:58, 8 April 2013
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 |
|---|---|
| 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 the
|
| Slide 3:
System Requirement |
To record this tutorial
I am using
|
| Slide 4: | Flow over flat plate is a fundamental problem in fluid mechanics |
| Slide 5:
Flow over a flat plate diagram |
We can visualise the growth of boundary layer
Boundary layer is a very thin region above the body where the velocity is 0.99 times the free stream velocity. |
| Slide 6: Diagram of boundary conditions. | This is a diagram of flow over the flat plate
The boundary conditions are given as follows
Free stream velocity U = 1 m/s, and we are solving this for Reynolds no (Re) = 100 |
| Click on home>> OpenFoam >> Run >> Tutorials >> Incompressible >> SimpleFoam | Go to the home folder and click on the OpenFoam folder
Then go to the Run directory You will see Tutorials. Click on it. 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's open the pitzdaily case. |
| Zoom in | Let me zoom this. |
| Select 0, constant and system folders | Copy the three folders - 0, constant and system |
| Copy them | Copy this |
| Go back to SimpleFoam >> flatplate folder
Paste them there |
Now let us go one level back.
Paste these 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. | |
| I have already made the changes.
Let us open the blockMeshDict file The geometry is in meters. | |
| We have set the dimensions of the flatplate | |
| Simplegrading (1 3 1) | We can see that simpleGrading.
It is kept as (1 3 1) as we need a finer mesh near the plate. |
| Now close this.
Go two levels back. | |
| Similarly, make changes in the boundary condition names inside the files in the 0 folder.
These files have pressure, velocity and wall functions. | |
| To calculate the values of wall functions,
Let us go one level back. | |
| The system folder can be kept default
Let us close this | |
| 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 | Type cd space tutorials and press Enter. |
| Type cd incompressible | Type cd incompressible press Enter. |
| Type cd simpleFoam | 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 on left hand side | 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. Let me switch back to the slides. |
| Slide 6 : solver | The solver we are using here is: simpleFoam.
SimpleFoam is a steady state solver for incompressible and turbulent flows |
| Demo :
type simpleFoam |
Let me switch back to the terminal window.
In the terminal window ,type simpleFoam and press Enter.
|
| 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 top drop down menu,
in the Active Variable Control menu, change from solid color to capital U |
| You can see the initial condition of velocity | |
| VCR control | Now on top of the ParaView window, you will see the VCR controls. |
| 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 Colour legend | This is the velocity contour
Toggle on the Color legend |
| Color legend left hand side top icon | To do this, click on the colour legend icon in 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 > Commom > glyph | To visualize the Vector Plot,
go to the Filters Menu > Common > glyph |
| Go to the Properties in Object Inspector menu | |
| 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 zoomToBox option |
| And zoom over any area that you desire | |
| Parabolic variation of vector plot | We can see the parabolic variation of vector plot as the flow moves over the plate. |
| Delete the vector plot | Delete this. Now delete the vector plot. |
| Correesponding 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 | You can also plot the variation of velocity along the x and y axes using the plot data over line. |
| Slide 9
Summary |
This brings us to the end of the tutorial.
In this tutorial we learnt :
|
| Slide 10:
Assignment |
As an Assignment,
Create a geometry of flow over a flat plate Refine the grid spacing near the plate |
| Slide 11 :
About Spoken tutorials |
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. |
| Slide 12:
About Spoken tutorials |
The Spoken Tutorial Project Team
-Conducts workshops using spoken tutorials -Gives certificates to those who pass an online test -For more details, please write to contact@spoken-tutorial.org |
| Slide 13:
Acknowledgement
|
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. |
