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

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Time Narration
00:01 Hello and welcome to the spoken tutorial on Creating Curved geometry in OpenFOAM
00:06 In this tutorial I will show you
00:09 Steps for creating a curved geometry in openfoam
00:14 Viewing the results in paraview
00:17 To record this tutorial
00:19 I am using Linux Operating system Ubuntu version 10.04. OpenFOAM version 2.1.0
00:28 ParaView version 3.12.0
00:32 We will create a geometry for flow over cylinder.
00:36 Note that I am using this case just for explanation.
00:41 The cylinder is in a form of a semi circle.
00:45 Meshing is a body fitted grid.
00:49 The entire geometry is divided into blocks.


00:54 We break the semi circle into equal number of parts.
00:58 Now minimise this
01:03 Open a blockMeshDict file of the previous tutorial
01:08 I have already opened it
01:12 Scroll down, for simple geometries you can see that edges is kept empty
01:20 Now Create a new blockMeshDict file
01:23 To do this let us minimise this first
01:27 Now Right click > create document > empty file
01:34 Name this as blockMeshDict.
01:40 Note that M and D here are capital
01:46 Open this
01:51 Now you can copy the initial few lines from the lid driven cavity upto convertTometers
01:58 Go up copy this upto convertToMeters
02:04 Copy this and paste it in the new blockMeshDict file
02:12 Now change the convert to meters from point one to one
02:18 As our geometry is in meters we will keep this as one
02:24 Now press enter , press enter again
02:28 After this you need to enter the co-ordinates of the geometry in vertices
02:35 Let me switch back to the slide. Note that the points should be ordered in such a way starting from 0,1,2,3, 4 and so on. as shown in the figure
02:47 Minimise the slide. Now type vertices in the blockMeshDict file and press Enter
02:56 Insert the open bracket and Press Enter
03:00 Now enter the co-ordinates of a geometry as shown in the diagram.
03:05 Let me switch back to the slides
03:08 For explanation I will use right half of the semi-circle
03:12 Enter the values for the points in the figure starting from 0
03:16 Let me switch back to the blockMeshDict file
03:20 leave some space and enter the co-ordinates of point 0
03:27 Open close bracket enter 0.5 (space) 0 (space) 0. Press Enter
03:36 Again leave some space , open close bracket
03:39 Enter co-ordinates for point 1 (space) 0 (space) 0. Press enter
03:45 Now leave two vertical spaces , again press Enter, again press Enter
03:51 leave some space and enter the co-ordinate for point number 4
03:57 Open, close bracket, enter 0.707 (space) 0.707 (space) 0
04:05 Press Enter. Leave some space
04:09 Open, close bracket
04:10 Enter the co-ordinates for the point 5
04:13 Enter 0.353 (space) 0.353 (space) 0, press Enter
04:22 Now leave 4 vertical spaces and enter co-ordinates for point number 9
04:27 1 2 3 4 , again press Enter, leave some space
04:34 Open, close bracket
04:36 Enter 0 (space) 1 (space) 0, press Enter
04:42 Leave some space
04:44 Enter co-ordinates for point number 10
04:46 Open close bracket 0 (space) 0.5 (space) 0 and press Enter
04:54 Similarly enter the co-ordinates for the remaining points in the geometry.
05:00 Insert a close bracket put a semi-colon and press Enter
05:05 Again press Enter
05:06 Now type blocks, press enter
05:13 Insert a open bracket press enter
05:16 Let me switch back to the slides
05:20 TheBlock numbers are circled as shown in the figure
05:24 Now let me switch back to the blockMeshDict file
05:28 Leave some space
05:30 Now enter the type of block i.e. Hex leave some space
05:37 Now enter the points for the blocks
05:41 Open, close brackets
05:43 Leave some space, the simple grading can be kept as (1 1 1) and press enter
05:55 For creating the blocks please refer to the tutorial on creating simple geometry in OpenFOAM
06:02 Note that there will be more number of blocks in this example
06:07 Now insert a close bracket
06:10 Insert a semi-colon, and press Enter. Again press Enter
06:16 In the next line type edges and press Enter
06:22 insert a open bracket and press Enter
06:26 Here you need to enter the points which are the end points of the arcs
06:31 Leave some space and type arc leave some space type the points which are the end points of the arc
06:40 Let me switch back to the slide. Now insert the end points of the arc
06:46 In this figure, we start with arc 0 5
06:52 Let me switch back to the blockMeshDict file
06:56 Enter 0 space 5
06:59 Leave some space insert open, close bracket
07:04 In the bracket enter the co-ordinate of any intermediate point in between the two arc points.
07:11 Now let me switch back again to slides
07:14 In the figure you can see that you have to pick up a point in between the two end points of the arc.
07:23 In this geometry I have picked up right half of the circle
07:28 Using simple geometric relations you can find the co-ordinates of the intermediate point as shown in the semi-circle
07:38 Similarly you can repeat the procedure for rest of the semi-circle geometry
07:45 Now let me switch back to the blockMeshDict file
07:48 press Enter
07:50 Note that there are more number of arcs in this example
07:55 Insert a close bracket
07:58 Insert a semi -colon press Enter again press Enter
08:02 Now enter the boundary patches after arcs
08:06 Refer to the tutorial on Simple geometry in OpenFOAM, for entering the boundary patches
08:12 Enter boundary,press Enter
08:15 Insert open bracket press Enter. Insert close bracket semi-colon, press Enter
08:21 Again press Enter
08:24 Now In the next line type mergePatchPairs
08:29 Note that P here is capital
08:31 Press Enter
08:33 Insert a open bracket, press Enter
08:36 Since there are no patches to be merged this can be kept empty
08:40 Insert a close bracket
08:42 Insert a semi -colon and press Enter
08:46 Let me switch back to the slides
08:49 Similarly enter the co-ordinate points for the points in the front face of unit thickness of the geometry as shown in the figure
08:57 Now open a Command terminal
09:00 In the command terminal type the path for your case
09:04 I have already set the path for the tutorial case of flow over cylinder
09:10 In the terminal type blockMesh for meshing the geometry and press enter
09:18 Meshing is done
09:20 Now type paraFoam in the terminal and press enter to view the geometry
09:26 Let me drag this to the capture area
09:30 Now on left-hand side of object inspector menu click Apply
09:36 geometry will be created as seen in the paraview window
09:41 Scroll down the Object inspector menu
09:44 Check or uncheck the Mesh field box
09:49 You can see different regions of the geometry.
09:53 You can also see the wire frame of the geometry
09:56 On top of the active variable control menu, in the drop down menu change from Surface to wireframe
10:05 You can see the wireframe model of the geometry
10:11 Close this. Let me switch back to the slides
10:16 In this tutorial we learnt:
10:17 How to create a curved geometry.
10:20 How to enter points for edges in OpenFOAM
10:24 This brings us to the end of the tutorial
10:28 As an Assignment
10:29 Create a geometry with inner semi-circle of radius 2 meters and outer semi- circle of radius 4 meters and View the geometry in paraview
10:42 Watch the video available at this URL: http://spoken-tutorial.org/What_is_a_Spoken_Tutorial
10:45 It summarizes the Spoken Tutorial project.
10:48 If you do not have good bandwidth, you can download and watch it.
10:53 The Spoken Tutorial Project Team
10:56 Conducts workshops using spoken tutorials
10:58 Gives certificates to those who pass an online test
11:02 For more details, please write to contact@spoken-tutorial.com
11:09 Spoken Tutorials are part of Talk to a Teacher project,
11:13 It is supported by the National Mission on Education through ICT, MHRD, Government of India.
11:18 More information on the same is available at the following URL link http://spoken-tutorial.org/NMEICT-Intro
11:23 This is Rahul Joshi from IIT BOMBAY signing off. Thanks for joining

Contributors and Content Editors

DeepaVedartham, Gaurav, PoojaMoolya, Sandhya.np14, Sneha