PoojaMoolya at 13:13, 20 February 2017

2017-02-20T13:13:27Z

Sandhya.np14 at 05:24, 7 July 2016

2016-07-07T05:24:46Z

Sandhya.np14 at 05:23, 7 July 2016

2016-07-07T05:23:04Z

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Pratik kamble at 11:46, 27 November 2015

2015-11-27T11:46:54Z

Pratik kamble: Created page with "{| border=1 | '''Time''' | '''Narration''' |- | 00:01 | Hello and welcome to the spoken tutorial on '''Unstructured Mesh generation using GMSH.''' |- | 00:06 | In this tutor..."

2015-11-27T11:46:35Z

Created page with "{| border=1 | '''Time''' | '''Narration''' |- | 00:01 | Hello and welcome to the spoken tutorial on '''Unstructured Mesh generation using GMSH.''' |- | 00:06 | In this tutor..."

New page

{| border=1
| '''Time'''
| '''Narration'''

|-
| 00:01
| Hello and welcome to the spoken tutorial on '''Unstructured Mesh generation using GMSH.'''

|-
| 00:06
| In this tutorial we will learn to
* Create an '''unstructured mesh '''in '''GMSH'''
* Create plane''' surfaces'''
* Basic manipulations using the file with extension '''.geo'''

|-
| 00:18
| To record this tutorial I am using
* '''Ubuntu Linux Operating system 14.04'''
* '''GMSH version 2.8.5'''
* '''OpenFOAM version 2.4.0'''

|-
| 00:30
| This tutorial is a continuation of :
Creation of sphere using GMSH

|-
| 00:35
| We have already learnt to create a sphere using GMSH earlier.

|-
|00:40
| If you don't know how to do so, refer to the '''GMSH '''spoken tutorials in the '''OpenFOAM '''series on this website.

|-
| 00:48
| Here is our problem statement.This picture shows the flow direction and boundary faces.
We will now learn how to create an '''unstructured mesh '''using '''GMSH'''.

|-
| 01:01
| Note that the size of the domain is 45 X 30 X 30, and the radius of the sphere is 1.However, these dimensions can vary from problem to problem.The points for the domain are as shown here.

|-
| 01:18
| Let us switch to '''GMSH '''now.Here is the sphere we created earlier.

|-
| 01:24
| I have also created all the points and lines of the domain.To create the points of the domain, kindly refer to the tutorial mentioned earlier.

|-
| 01:36
| Now, select the option '''plane surface. '''Then select the respective edges for the surface. The selection will be displayed in red.

|-
|01:48
| Press '''E''' on the keyboard to execute the selection.On doing so, we can see the dotted lines.

|-
| 01:57
| Repeat the process until all surfaces are created.

|-
|02:02
| Now, select the option '''Physical Groups''', then '''Add''' and then '''surface.'''

|-
| 02:10
| Now, select these four faces for the '''wall''' and press '''E '''on the keyboard.

|-
| 02:17
| Select the front face for '''inlet '''and press '''E. '''

|-
| 02:21
| Select the back face for''' outlet''' and press '''E. '''

|-
| 02:26
| Now close '''GMSH.'''

|-
| 02:29
| Now, open the '''sphere1.geo '''file in '''gEdit Text Editor.'''Note that there are additions to this file.
Also note that the identification numbers for the entities is in continuation of the earlier series.

|-
| 02:47
| As done earlier, replace the numerical values.Use the letter''' d''' for the domain''' mesh''' variable.

|-
| 02:56
| Then, at the beginning of the file type '''d = 0.5;'''

|-
| 03:02
| To name the boundaries, change the numerical value with your desired name, as demonstrated.

|-
| 03:09
| The first physical surface, we made in the interface was '''wall'''.So, here, we will replace it with '''wall.'''

|-
| 03:18
| The second physical surface, we made in the interface was '''inlet'''.Hence, here, we will replace it with '''inlet.'''

|-
| 03:27
| The third physical surface, we made in the interface was '''outlet.'''So, here, we will replace it with '''outlet.'''

|-
| 03:36
| Now type''', Surface Loop''',''' ID''' which is the next integer in round brackets equals the IDs of all surfaces of the domain in braces which is 43, 45, 47, 49, 51 and 53

|-
|03:59
| For definition of volume, use '''Volume, ID''' which is the next integer in round brackets equals the IDs of the two surfaces in braces Which is 29 and 57.

|-
| 04:20
| For physical volume, use '''Physical Volume''', '''ID''' which is the next integer in round bracketsequals the '''IDs''' of the volume in braces which is 58.

|-
| 04:35
| Save this file and close it. Now, using the terminal reopen '''GMSH '''by''' '''typing:
'''gmsh sphere1.geo '''and press '''Enter'''

|-
| 04:48
| In '''GMSH''', a bottom to top approach is followed
* That is, first '''1D mesh''' is created
* Using '''1D mesh, 2D mesh '''is created
* Using '''2D mesh, 3D mesh''' is created

|-
| 05:02
| For '''1D mesh''' creation, press '''F1''' key.

|-
| 05:06
| For '''2D mesh''' creation, press '''F2''' key.

|-
| 05:10
| For '''3D mesh''' creation, press '''F3''' key.

|-
| 05:14
| This may take a while. Watch the progress in the status bar.This shows '''Done '''now.

|-
| 05:22
| Once the '''mesh '''is created, we need to optimize it to remove faulty cells.

|-
| 05:27
| For optimization click on Modules , then Mesh and then on '''Optimize 3d Netgen '''option

|-
|05:36
| This may also take a while.Once again, watch the progress in the status bar.

|-
| 05:43
| To save the '''mesh''' go to '''File, Save mesh''' and close the '''terminal.'''

|-
| 05:51
| Create '''OpenFOAM''' '''case''' directory without the '''constant '''folder.In the '''case''' directory, copy the newly created file '''sphere1.msh'''

|-
| 06:01
| Using the '''terminal''' window, go to the '''case''' directory of this problem.

|-
| 06:06
| Once you are in the '''case''' directory,Type: '''gmshToFoam sphere1.msh '''
To convert the '''mesh'''

|-
| 06:16
| Ensure that the same '''boundary names''' are there in the files of folder 0, before proceeding to the next step.

|-
| 06:24
| Let us summarise.
In this tutorial we have learnt to:

* Create an '''unstructured mesh '''in '''GMSH'''
* Create plane''' surfaces'''
* Basic manipulations using the file with''' '''extension''' .geo'''

|-
| 06:38
| As an assignment,Make refinement in the''' mesh''' by changing the values of:
'''s, d '''and '''Mesh.CharacteristicLengthFromCurvature'''

|-
| 06:49
| '''OpenFOAM''' series is created by the '''FOSSEE Project, IIT Bombay'''. '''FOSSEE''' stands for Free and Open Source Software for Education.

|-
| 06:58
| This project promotes the use of free and open source software tools. For more details, please visit: [http://fossee.in/ http://fossee.in/]

|-
| 07:07
| The video at this link summarises the Spoken Tutorial project. Please download and watch it.

|-
| 07:13
| The Spoken Tutorial Project Team conducts workshops and gives certificates on passing online tests. For more details, please write to us.

|-
| 07:22
| Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India. More information on this Mission is available at this link.This is Pavan Mehta from FOSSEE Project, IIT BOMBAY signing off. Thanks for joining.

|}

@@ Line 10: / Line 10: @@
 | 00:06
 | In this tutorial, we will learn to:
-* Create an '''unstructured mesh '''in '''GMSH'''
+Create an '''unstructured mesh '''in '''GMSH'''
-* Create plane''' surfaces'''
+Create plane''' surfaces'''
-* Basic manipulations using the file with extension '.geo'.
+Basic manipulations using the file with extension '.geo'.
 |-
 | 00:18
 | To record this tutorial, I am using:
-* '''Ubuntu Linux Operating system''' 14.04
+'''Ubuntu Linux Operating system''' 14.04
-* '''GMSH''' version 2.8.5
+'''GMSH''' version 2.8.5
-* '''OpenFOAM''' version 2.4.0
+'''OpenFOAM''' version 2.4.0
 |-
 | 00:30
 | This tutorial is a continuation of
-'''Creation of sphere using GMSH
+'''Creation of sphere using GMSH'''.
 '''.
 |-
 | 00:35
@@ Line 36: / Line 36: @@
 |-
 | 00:48
-| Here is our problem statement. This picture shows the flow direction and '''boundary face'''s.
+| Here is our problem statement. This picture shows the flow direction and '''boundary faces'''.
 We will now learn how to create an '''unstructured mesh '''using '''GMSH'''.
@@ Line 186: / Line 186: @@
 | Let us summarize.
 In this tutorial, we have learnt to:
-* Create an '''unstructured mesh '''in '''GMSH'''
+Create an '''unstructured mesh '''in '''GMSH'''
-* Create plane''' surfaces'''
+Create plane''' surfaces'''
-* Basic manipulations using the file with''' '''extension''' .geo'''.
+Basic manipulations using the file with''' '''extension''' .geo'''.
 |-

@@ Line 12: / Line 12: @@
 * Create an '''unstructured mesh '''in '''GMSH'''
 * Create plane''' surfaces'''
-* Basic manipulations using the file with extension '''.geo'''.
+* Basic manipulations using the file with extension '.geo'.
 |-

@@ Line 29: / Line 29: @@
 | 00:35
 | We have already learnt to create a sphere using GMSH earlier.
 |-

OpenFOAM/C3/Unstructured-mesh-generation-using-Gmsh/English-timed - Revision history

PoojaMoolya at 13:13, 20 February 2017

Sandhya.np14 at 05:24, 7 July 2016

Sandhya.np14 at 05:23, 7 July 2016

Pratik kamble at 11:46, 27 November 2015

Pratik kamble: Created page with "{| border=1 | '''Time''' | '''Narration''' |- | 00:01 | Hello and welcome to the spoken tutorial on '''Unstructured Mesh generation using GMSH.''' |- | 00:06 | In this tutor..."