Difference between revisions of "OpenFOAM/C2/Creating-simple-geometry-in-OpenFOAM/English-timed"
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− | | Hello and welcome to the spoken tutorial on '''creating | + | | Hello and welcome to the '''spoken tutorial''' on '''creating simple geometry in OpenFOAM'''. |
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| 00:06 | | 00:06 | ||
− | | In this tutorial I will show you | + | | In this tutorial, I will show you: |
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| 00:08 | | 00:08 | ||
− | | How to create | + | |* How to create '''simple geometry''' |
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| 00:11 | | 00:11 | ||
− | | How to view the geometry in '''paraview ''' | + | |* How to view the geometry in '''paraview'''. |
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| 00:15 | | 00:15 | ||
− | | To record this tutorial | + | | To record this tutorial, |
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| 00:16 | | 00:16 | ||
− | | I am using '''Linux Operating system Ubuntu''' version 10.04 | + | | I am using: |
+ | * '''Linux Operating system Ubuntu''' version 10.04 | ||
+ | * '''OpenFOAM''' version 2.1.0 | ||
+ | * '''ParaView''' version 3.12.0 | ||
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| 00:27 | | 00:27 |
Revision as of 13:08, 21 June 2016
Time | Narration |
00:01 | Hello and welcome to the spoken tutorial on creating simple geometry in OpenFOAM. |
00:06 | In this tutorial, I will show you: |
00:08 | * How to create simple geometry |
00:11 | * How to view the geometry in paraview. |
00:15 | To record this tutorial, |
00:16 | I am using:
|
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, |
00:40 | 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 space constant and press Enter |
01:03 | Now type ls and press Enter |
01:06 | In this there is another folder called as polymesh |
01:10 | Now type cd space 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 space 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 |
01:59 | The blocks are numbered starting from 0 as shown in the figure |
02:08 | Note that in OpenFOAM for creating a 2D geometry 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 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 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 |
03:30 | Again press Enter in the 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 |
04:56 | close the bracket and insert a semicolon after it. Press Enter,again press Enter |
05:03 | Below vertices are the blocks. Type blocks and press Enter. Insert a Open bracket and press enter |
05:16 | 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 the clockwise sense |
05:31 | We are using here hexa hedal blocks for meshing. |
05:34 | Now type hex leave some space in brackets enter 0 space 1 2 3 4 5 6 7 again leave some space |
05:53 | Note that for 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 open close brakets enter 30 space 30 space 1 leave some space , 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 leave some space 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 space 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 for 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 |
10:18 | The complete blockMeshDict file is as shown here. |
10:26 | Close both the blockMeshDict files |
10:29 | Note that the command terminal will not work until blockMeshDict file is closed |
10:35 | Switch back to the terminal. Now type cd (dot) (dot) twice to return back to the cavity folder. Now Mesh the geometry |
10:45 | 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 |
10:59 | This will open the ParaView window |
11:03 | Now On the left hand side click Apply on object inspector menu thus you can see the geometry. |
11:13 | Now let me switch back to the slides |
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 1and 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. |
11:46 | 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