OpenFOAM/C2/Creating-simple-geometry-in-OpenFOAM/English-timed

Time'	Narration
00:01	Hello and welcome to the spoken tutorial on creating a simple geometry in OpenFOAM
00:06	In this tutorial I will show you
00:08	How to create a simple geometry
00:11	How to view the geometry in paraview
00:15	To record this tutorial
00:16	I am using Linux Operating system Ubuntu version10.04 OpenFOAM version 2.1.0 ParaView version 3.12.0
00:27	In CFD the Pre-processing part consists of creating geometry and meshing it.
00:33	Let us take the Lid driven cavity case of the previous tutorial as an example.
00:38	Recall the path for he earlier tutorial,
00:41	I have already opened the command terminal and entered the path for lid driven cavity
00:48	There are three folders 0,constant,and system Geometry is inside the polymesh folder of constant
00:55	In the command terminal type cd constant and press enter
01:03	NowType ls and press enter
01:06	In this there is another folder called as polymesh
01:10	Now type cd polymesh and press enter
01:18	Now type ls and press enter
01:22	This contains the geometry file called as blockMeshDict
01:26	Open the blockMeshDict file with any editor of your choice
01:30	In the terminal type gedit blockMeshDict( Note that M and D are capital) and press enter
01:45	Let me drag this to the capture area
01:49	Now Minimise this
01:53	Let me switch back to the slides
01:55	In openfoam the entire geometry is broken into blocks
02:02	The blocks are numbered starting from 0 as shown in the figure
02:08	Note that in OpenFOAM for creating a 2D geometry
02:12	you need to give a a unit cell thickness value in the z-axis.
02:19	lid driven cavity is of length 1 and height 1 minimise the slide
02:29	On your desktop create an empty file by
02:33	right click > create document > Empty file name this as blockMeshDict. (Note that M and D here are capital).
02:48	Open this. Now Copy the data from the original lid driven cavity blockMeshDict file
02:55	to the new blockMeshDict file from line 0.
02:59	Scroll up line 0 upto convertTometers. Copy this and paste it here.
03:15	Scroll down. Now leave some space after converttometers.
03:21	Enter 1 as the geometry is in meters. Insert a semicolon and press enter
03:31	Again press Enter in file type vertices and press enter
03:39	Insert the open bracket and press enter
03:43	Press the tab key. Start with point 0, insert open, close brackets enter
03:52	(0 space 0 space 0) and press enter. Again press tab key open close bracket .
04:02	Move towards point 1 in positive x-axis and enter (1 space 0 space 0) and press enter
04:12	Again press tab key open close bracket .move towards point 2 in positive x-y plane and enter (1 space 1 space 0) and press enter
04:26	Again press tab key open close bracket enter the 3rd point in positive y axis (0 space 1 space 0 ) press enter
04:39	Again press tab key enter the 4th point on the front face, open close bracket (0 space 0 space 0.1) and press enter
04:51	Similarly enter the other points with one unit value in the positive z -axis
04:57	close the bracket and insert a semicolon after it. Press enter,again press enter
05:04	Below vertices are the blocks. Type blocks and press enter. Insert a Open bracket and press enter
05:17	let me switch back to the slides
05:19	Note that Lid driven cavity is taken as a single block
05:24	Let me switch back to blockmeshdict
05:27	Enter the points for the blocks in theclockwise sense
05:31	We are using here hexa hedal blocks for meshing.
05:34	Now type hex leave some space
05:39	in brackets enter ( 0 space 1 2 3 4 5 6 7 ) again leave some space
05:54	Note thatFor multiple blocks the points will be more.
05:58	After this enter the grid points in the x,y,and z directions
06:02	In brackets enter (30 space 30 space 1) ,you can modify the grid as an when needed
06:16	Grid point in z-axis can be taken as one
06:22	Now Leave some space and type simple grading open close bracket enter (1 space 1 space 1)
06:36	This is the grid spacing in the x y and z direction. Press enter.
06:43	Insert Close bracket insert a semicolon and press enter
06:48	Again press enter.Now type edges, and press enter.
06:55	As this is a simple geometry edges can be kept empty
07:00	Insert open bracket press enter close the bracket ,insert a semicolon and press enter
07:07	Again press enter. Below edges are the boundary conditions.
07:11	Here you need to enter the boundary name for the faces
07:15	Type boundary and press enter .
07:19	insert a open bracket and press enter
07:23	Now Let me switch back to the slides
07:26	In the geometry the upper wall is moving and other three walls are fixed.
07:31	The front and back faces are named as empty as this is a 2D problem
07:39	Open the New blockMeshDict file again
07:42	In boundary put the name of the patch as moving wall . Press enter
07:51	Now Insert a open curly bracket and press enter
07:56	Now Enter the type for the moving wall , enter type wall
08:06	insert a semicolon and press enter
08:09	Now insert open bracket, and press enter. Press the tab key. Open close bracket.
08:20	In this bracket enter the pointfor faces
08:24	Let me switch to the slide
08:27	Note that order of the points should be in such a way that the thumb should be normal to the face
08:34	And fingers making a curl as shown in the figure .
08:39	The curl can be clockwise or anti- clockwise
08:43	Also note that the points should match with the points inserted in vertices
08:48	Now let me switch back to the new blockmeshdict file .
08:52	Now in the faces enter (3 space 7 space 6 space 2).
09:01	Let me switch back to the slide. These are the point for the moving wall 3,7,6,2.
09:09	Minimise this. Note that you can start from any point on that face. Now press enter
09:17	Close the bracket again press enter. Close the curly bracket.
09:22	Another note we need to enter a semi- colon after you insert the points, a faces now after the curly brackets press enter again press enter
09:35	Now Similarly enter boundary condition and faces for the fixed wall
09:40	Being a 2D problem the type of boundary for front and back face can be kept as empty.
09:46	Refer to the figure in the slide. For entering the points. Minimise this
09:52	Insert the closed brackets put a semicolon and press enter again press enter.
09:59	Now type mergePatchPairs and press enter.
10:04	Since their are no patches to merge it can be kept empty
10:08	Insert open close bracket. Insert a semi-colon and press enter.
10:14	We are done with creating the blockmeshdict file. Save this
10:19	The complete blockMeshDict file is as shown here.
10:26	Close the both the blockMeshDict files
10:29	Note that the command terminal will not work until blockMeshDict file is closed
10:35	Come back to the termina.l now type cd (dot) (dot) twice to return back to the cavity folder. Now Mesh the geometry
10:46	To do this in a terminal type: blockMesh and press enter
10:53	Now View the geometry by typing in the command terminal paraFoam and press enter
11:00	This will open the ParaView window
11:04	Now On the left hand side click Apply on object inspector menuthus you can see the geometry.
11:13	now let me switch back to theslides
11:16	In this tutorial we learnt:
11:18	Creating a simple geometry in OpenFOAM
11:22	Viewing the geometry in Paraview
11:25	This brings us to the end of the tutorial
11:29	As an Assignment
11:31	Change the direction of lid driven cavity ,Change the grid size to (50 50 1)and View the geometry in paraview
11:41	Watch the video available at this URL: http://spoken-tutorial.org/What_is_a_Spoken_Tutorial
11:44	It summarizes the Spoken Tutorial project.
11:47	If you do not have good bandwidth, you can download and watch it.
11:51	The Spoken Tutorial Project Team
11:53	-Conducts workshops using spoken tutorials
11:55	-Gives certificates to those who pass an online test
11:59	-For more details, please write to contact@spoken-tutorial.org
12:05	Spoken Tutorial project is part of Talk to a Teacher project,
12:09	It is supported by the National Mission on Education through ICT, MHRD, Government of India.
12:15	More information on the same is available at the following URL link http://spoken-tutorial.org/NMEICT-Intro
12:19	This is Rahul Joshi from IIT BOMBAY signing off. Thanks for joining.

Contributors and Content Editors

DeepaVedartham, Gaurav, PoojaMoolya, Pratik kamble, Sandhya.np14, Sneha