OpenFOAM/C3/Flow-over-a-flat-plate/English-timed

Time	Narration
00:01	Hello and welcome to the spoken tutorial on Flow over a flat plate using OpenFOAM.
00:06	In this tutorial, I will teach you about: Geometry of the flat plate Changing the grid spacing in meshing Postprocessing results in ParaView and Visualizing using Vector Plot.
00:19	To record this tutorial, I am using: Linux Operating system Ubuntu version 12.04. OpenFOAM version 2.1.1 and ParaView version 3.12.0
00:30	Flow over flat plate is a fundamental problem in fluid mechanics.
00:35	We can visualize the growth of the boundary layer. Boundary layer is a very thin region above the body
00:41	where the velocity is 0.99 times the free stream velocity.
00:46	This is a diagram of flow over the flat plate.
00:49	The boundary conditions are given as follows. You have the Inlet, the Plate, Top – which is the Farfield and Outlet – which is the pressure outlet boundary.
01:00	The Free stream velocity U = 1 m/s' and we are solving this for Reynolds number (Re) = 100'.
01:08	Now let us go to the home folder. In the home folder, click on the OpenFoam folder.
01:15	Then go to the Run directory. You will see Tutorials. Click on it. Scroll down and then click on Incompressible. Scroll down.
01:27	You will see the simpleFoam folder. Click on it. This solver suits our case.
01:34	In this, create a folder by the name flatplate. Right click - Create New Folder - flatplate.
01:44	Now, let's open the pitzdaily case.
01:47	Let me zoom this. Copy the three folders - 0, constant and system. Copy this.
01:56	Now let us go one level back. Paste these three folders inside the flatplate folder.
02:05	Open the constant folder and then the polyMesh folder.
02:10	Change the geometry and boundary condition names in the blockMeshDict file.
02:15	I have already made the changes. Let us open the blockMeshDict file . Scroll down. The geometry is in meters.
02:25	We have set the dimensions of the flatplate.
02:29	We can see the simpleGrading. It is kept as (1 3 1) as we need a finer mesh near the plate.
02:35	Now close this. Go two levels back.
02:41	Similarly, make changes in the boundary condition names inside the files in the '0' folder.
02:48	These files have pressure, velocity and wall functions.
02:54	To calculate the values of wall functions, please refer to the earlier tutorial in the OpenFoam series. Let us go one level back.
03:03	The system folder can be kept default. Let us close this.
03:09	Now let us open the terminal window. In the terminal window, type "run" and press Enter.
03:16	Type cd space tutorials press Enter.
03:21	Type cd incompressible press Enter.
03:25	Type cd space simpleFoam press Enter.
03:31	Now type "ls" and press Enter.
03:34	We can see the flatplate folder.
03:37	Now, type cd space flatplate and press Enter.
03:42	Now type "ls" and press Enter.
03:45	You can see the three folders 0, constant and system.
03:49	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.
03:58	Press Enter. Meshing has been done.
04:01	Note that if there is some error in the blockMesh file, it will be shown in the terminal window.
04:07	To view the geometry, type “paraFoam”, press Enter.
04:13	After the ParaView window opens, on the left hand side of the object inspector menu, click Apply.
04:21	We can see the geometry. Close the ParaView window. Let me switch back to the slides.
04:28	The solver we are using here is simpleFoam. SimpleFoam is a steady state solver for in compressible and turbulent flows.
04:37	Let me switch back to the terminal window. In the terminal window, type "simpleFoam" and press Enter.
04:45	You will see the iterations running in the terminal window.
04:51	Once the solving is done, type "paraFoam" to view the results.
04:55	On the left hand side of the Object Inspector menu, click Apply to view the geometry.
05:01	Scroll down the properties panel of the Object Inspector menu for time step, regions and fields.
05:08	To view the contours from the top drop down menu, in the Active Variable Control menu, change from solid color to capital 'U'.
05:19	You can see the initial condition of the velocity.
05:23	Now on top of the ParaView window, you will see the VCR control.
05:28	Click on the Play button.
05:33	You will see the contour of Pressure or Velocity on the flat plate accordingly.
05:39	This is the velocity contour. Toggle on the Color legend.
05:43	To do this, click on the color legend icon on the Active Variable Control menu.
05:50	Click Apply in the Object inspector menu.
05:53	In the Object inspector menu, click on Display.
05:57	Scroll down and click on Rescale to data range.
06:03	Let me shift this Color legend on top to visualize the Vector Plot. Go to the Filters Menu > Common > glyph.
06:15	Go to the Properties in Object Inspector menu.
06:20	Click Apply on the left hand side of Object Inspector Menu.
06:24	You can change the number of vectors by changing their size at the bottom.
06:29	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
06:41	Again, click the Apply button.
06:44	Now let me zoom this.
06:46	To do this, in the Active Variable Control menu, click on zoomToBox option.
06:52	And zoom over any area that you desire.
06:58	We can see the parabolic variation of vector plot as the flow moves over the plate.
07:04	Delete this. Now delete the vector plot.
07:09	Also, we can see that the color near to 1 corresponds to the velocity of 0.99 times the free stream velocity.
07:17	You can also plot the variation of velocity along the X and Y axes using the plot data over line.
07:26	This brings us to the end of the tutorial. In this tutorial, we learnt: Geometry and meshing of the flat plate geometry and Vector plotting in ParaView.
07:37	As an Assignment- Create a geometry of flow over a flat plate. Refine the grid spacing near the plate.
07:45	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.
07:55	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
08:08	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.
08:17	More information on this mission is available at this URL: http://spoken-tutorial.org/NMEICT-Intro. This is Rahul Joshi from IIT Bombay, signing off. Thanks for joining.

Contributors and Content Editors

DeepaVedartham, PoojaMoolya, Pratik kamble, Sandhya.np14