OpenFOAM/C3/Creating-and-Meshing-aerofoil-in-Gmsh/English-timed - Revision history

PoojaMoolya at 13:10, 20 February 2017

2017-02-20T13:10:54Z

Sandhya.np14 at 12:55, 5 July 2016

2016-07-05T12:55:06Z

Sandhya.np14 at 12:26, 5 July 2016

2016-07-05T12:26:29Z

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Pratik kamble: Created page with " {| Border=1 | '''Time''' | '''Narration''' |- |00:01 | Hello and welcome to the spoken tutorial on '''Creating and Meshing an aerofoil in Gmsh''' |- | 00:08 | In this tutor..."

2016-03-30T06:41:01Z

Created page with " {| Border=1 | '''Time''' | '''Narration''' |- |00:01 | Hello and welcome to the spoken tutorial on '''Creating and Meshing an aerofoil in Gmsh''' |- | 00:08 | In this tutor..."

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{| Border=1
| '''Time'''
| '''Narration'''

|-
|00:01
| Hello and welcome to the spoken tutorial on '''Creating and Meshing an aerofoil in Gmsh'''

|-
| 00:08
| In this tutorial we will learn how to create an '''aerofoil '''using '''Gmsh'''

|-
| 00:14
| Mesh the created '''aerofoil'''

|-
| 00:17
| As a pre-requisite, the user should have basic knowledge of '''aerofoil '''and '''Gmsh.'''

|-
| 00:23
| If not, for '''Gmsh''' please see the tutorial on '''Installing and running Gmsh '''on the '''spoken tutorial''' website.

|-
| 00:31
| To record this tutorial, I am using
* '''Ubuntu Linux''' Operating system version 14.04 and
* '''Gmsh''' version 2.8.3

|-
| 00:42
| Let me introduce you to '''aerofoil'''.

|-
| 00:45
| '''Aerofoils''' are streamline shaped wings which are used in airplanes and turbo machinery.

|-
| 00:53
| These shapes are such that the '''drag force''' is a very small fraction of the '''lift'''.

|-
| 00:59
| This is a picture of an '''aerofoil'''.

|-
| 01:03
| The predefined coordinates for '''aerofoil''' are available in simple text file with '''.dat extension'''.

|-
| 01:11
| I will download the '''.dat''' file and '''Python script''' from this url:

|-
|01:19
| Let me open the website.

|-
| 01:22
| Download the '''.dat''' file and the '''Python script '''and go to the '''Downloads''' folder'''
|-
| 01:31
| Copy and paste both these files on the '''Desktop''' from the '''Downloads''' folder

|-
| 01:37
| Open the '''.dat''' file.

|-
| 01:40
| This file contains the calculated X and Y coordinates for each point that defines the '''aerofoil'''.
Z coordinate is kept as zero.

|-
| 01:51
| We need the X, Y and Z coordintes in '''Gmsh''' acceptable format.

|-
| 01:56
| This can be done manually but this is time consuming.

|-
|02:01
| Now open the '''Python script'''.

|-
| 02:04
| This '''Python script ''' converts the data in the '''.dat '''file and gives the ouput in a separate file which is understood by '''Gmsh'''.

|-
|02:14
| Now open the '''Terminal''' window. Type '''cd space Desktop'''

|-
| 02:21
| Now type '''python space dat2gmsh.py space''' the name of the '''dat''' file and press '''Enter'''.

|-
| 02:31
| Now type '''ls.'''We can see that a new file by the name '''naca5012xyz.dat .geo''' will be generated.

|-
| 02:43
| Open the '''geo''' file.

|-
| 02:46
| This contains the co-ordinates in '''Gmsh''' format.

|-
| 02:50
| Here '''nac_lc''' is the '''characterstic length''' which is defined in the first line which is '''0.005 '''

|-
| 02:59
| I will change this to '''0.5'''

|-
| 03:03
| This is because we require a coarser mesh.

|-
| 03:07
| You can change this value according to your mesh requirement. Now save this file.

|-
| 03:15
| In the '''terminal''' window, type '''gmsh space''' name of the '''geo''' file''' '''and press '''Enter'''.

|-
| 03:25
| This opens '''gmsh''' with the '''aerofoil'''.

|-
| 03:29
| Now zoom in, by scrolling at the tail end of the '''aerofoil'''.

|-
| 03:35
| You will note that the '''aerofoil''' has an open trailing edge.

|-
| 03:40
| Close '''gmsh'''. Now go back to the .'''geo''' file. Scroll down.

|-
|03:48
| We will add the last point and join it.

|-
| 03:53
| Now above '''spline''', enter '''Point open close bracket 1046 space = open close curly bracket 1.005comma space -0.0005 comma space 0.00000 comma space nac_lc close with semicolon '''

|-
|04:26
| Modify the '''spline''' as '''Spline(1000) = curly braces open 1000 colon 1046 comma 1000 close the curly bracket semicolon'''

|-
| 04:44
| Save the '''geo''' file.

|-
| 04:47
| Now, Open the modified file in '''Gmsh'''. We can see that the edge is joint.

|-
| 04:56
| Now we will make a boundary around the '''aerofoil''' using points.

|-
| 05:02
| Enter these coordinates 4, 3, 0 and change the prescribed '''mesh element size''' to '''0.5 '''

Press '''Enter.'''

|-
| 05:17
| Similarly, add the other points.

4 -3 0

-4 -3 0

-4 3 0

|-
| 05:29
| Now join the points with a straight line.

|-
| 05:44
| Now click on '''Plane surface '''and select the '''surface boundary. '''

|-
| 05:52
| Zoom in and select the '''aerofoil''' as the '''hole boundary'''.

|-
| 05:58
| Press '''e '''to end selection. You can see we have our surface.

|-
| 06:04
| Now we will extrude the surface to make it 3D. Go to '''Translate''', '''Extrude Surface.'''

|-
| 06:14
| A new window will appear asking for cordinates for translation.

|-
| 06:19
| Since we want to extrude the surface in positive Z direction,

* enter the coordinates for Z direction as 1
* and click on the boundary of the surface.

|-
| 06:30
| Press '''e '''to end selection.

|-
| 06:33
| Use the left click of the mouse to move the geometry.

|-
| 06:37
| You can see that the geometry has been extruded.

|-
| 06:42
| Close this. Close the '''gmsh '''window

|-
| 06:45
| Open the '''geo '''file.

|-
| 06:48
| Scroll down and go to '''Extrude.'''

|-
| 06:52
| Inside '''Extrude '''add these lines :

'''Layers{1};''' Press Enter

'''Recombine;'''Save this file.

|-
| 07:09
| This will ensure that the '''mesh''' is one '''element '''thick.

|-
| 07:14
| Now in the '''terminal '''window, open the '''geo '''file.

|-
| 07:19
| Now we have our geometry, we will do the meshing.

|-
| 07:23
| '''Gmsh''' automaticaly generates the mesh of the defined geometry.

|-
| 07:28
| Go to '''Mesh'''.

|-
| 07:30
| Click on '''1D mesh, 2D mesh '''and '''3D mesh.'''

|-
| 07:36
| The '''mesh''' has been generated.

|-
| 07:39
| You may notice that the mesh is finer near the '''aerofoil''' and gets coarser as we move towards the boundary.

|-
| 07:48
| We can also refine the mesh by clicking on the '''Refine by Splitting '''parameter in the mesh menu.

|-
| 07:56
| Now let us save our work.

|-
| 07:59
| Go to '''File''' menu and click on '''Save as. '''

|-
| 08:05
| A new window will appear. In the drop down, change to the '''mesh '''format.

|-
| 08:11
| And type the name the file as '''aerofoil.msh'''

|-
| 08:17
| Note that here '''msh '''stands for the file type '''mesh'''.

|-
| 08:22
| Click '''Ok ''' Again click '''Ok'''

|-
|08:26
| This brings us to the end of the tutorial.

|-
| 08:29
| As an '''assignment''' create another '''aerofoil''' by using different '''dat '''file for different '''aerofoil '''shapes.

|-
|08:37
| In this tutorial we learnt:
* How To create an aerofoil in Gmsh.
* How to do meshing in Gmsh

|-
| 08:45
| Watch the video available at this URL:
It summarizes the Spoken Tutorial project.

|-
| 08:52
| If you do not have good bandwidth, you can download and watch it.

|-
| 08:56
| The Spoken Tutorial Project Team.Conducts workshops using spoken tutorials

|-
| 09:00
| Gives certificates to those who pass an online test

|-
| 09:03
| For more details, please write to us contact@spoken-tutorial.org

|-
| 09:06
| Spoken Tutorials are part of Talk to a Teacher project,

|-
| 09:09
| It is supported by the National Mission on Education through ICT, MHRD, Government of India.

|-
| 09:15
| More information on the same is available at the following URL link [http://spoken-tutorial.org/NMEICT-Intro http://spoken-tutorial.org/NMEICT-Intro]

|-
| 09:19
| The script was written by Gautam Sharma and this is Rahul Joshi from IIT Bombay signing off. Thanks for joining.

|}

@@ Line 27: / Line 27: @@
 | 00:31
 | To record this tutorial, I am using:
-* '''Ubuntu Linux Operating system''' version 14.04 and
+'''Ubuntu Linux Operating system''' version 14.04 and
-* '''Gmsh''' version 2.8.3
+'''Gmsh''' version 2.8.3
 |-
@@ Line 71: / Line 71: @@
 |-
 | 01:40
-| This file contains the calculated X and Y coordinates for each point that defines the '''aerofoil'''.
+| This file contains the calculated X and Y coordinates for each point that defines the '''aerofoil'''. Z coordinate is kept as zero.
 Z coordinate is kept as zero.
 |-
@@ Line 172: / Line 171: @@
 |-
 | 05:02
-| Enter these coordinates 4, 3, 0  and change the '''prescribed mesh element size''' to '''0.5 '''.
+| Enter these coordinates 4, 3, 0  and change the '''prescribed mesh element size''' to '''0.5 '''. Press '''Enter.'''
 Press '''Enter.'''
 |-
 | 05:17
 | Similarly, add the other points.
 -3 0
 -4 -3 0
 -4 3 0
@@ Line 241: / Line 236: @@
 | 06:52
 | Inside '''Extrude''', add these lines:
 '''Layers{1};''' Press '''Enter'''.
 '''Recombine;''' '''Save''' this file.
@@ Line 317: / Line 310: @@
 |08:37
 | In this tutorial, we learnt:
-* How to create an '''aerofoil''' in '''Gmsh'''.
+How to create an '''aerofoil''' in '''Gmsh'''.
-* How to do '''meshing''' in '''Gmsh'''.
+How to do '''meshing''' in '''Gmsh'''.
 |-
@@ Line 339: / Line 332: @@
 |-
 | 09:03
-| For more details, please write to us at:
+| For more details, please write to us at:'''contact@spoken-tutorial.org'''
 '''contact@spoken-tutorial.org'''
 |-
@@ Line 352: / Line 344: @@
 |-
 | 09:15
-| More information on the same is available at the following URL:
+| More information on the same is available at the following URL:http://spoken-tutorial.org/NMEICT-Intro
 http://spoken-tutorial.org/NMEICT-Intro
 |-

@@ Line 203: / Line 203: @@
 |-
 | 06:04
-| Now, we will extrude the surface to make it 3D. Go to '''Translate''',  '''Extrude Surface.'''
+| Now, we will extrude the surface to make it 3D. Go to '''Translate >>  Extrude Surface.'''
 |-
 | 06:14
-| A new window will appear asking for cordinates for translation.
+| A new '''window''' will appear asking for the coordinates for translation.
 |-
 | 06:19
-| Since we want to extrude the surface in positive Z direction,
+| Since we want to extrude the surface in Z direction, enter the coordinates for Z direction as 1.
+And, click on the boundary of the surface.
-* enter the coordinates for Z direction as 1
-* and click on the boundary of the surface.
 |-
@@ Line 222: / Line 220: @@
 |-
 | 06:33
-| Use the left click of the mouse to move the geometry.
+| Use the left click of the '''mouse''' to move the '''geometry'''.
 |-
@@ Line 230: / Line 228: @@
 |-
 | 06:42
-| Close this. Close the '''gmsh '''window
+| Close this. Close the '''gmsh '''window.
 |-
@@ Line 242: / Line 240: @@
 |-
 | 06:52
-| Inside '''Extrude '''add these lines :
+| Inside '''Extrude''', add these lines:
-'''Layers{1};''' Press Enter
+'''Layers{1};''' Press '''Enter'''.
-'''Recombine;'''Save this file.
+'''Recombine;''' '''Save''' this file.
 |-
@@ Line 254: / Line 252: @@
 |-
 | 07:14
-| Now in the '''terminal '''window, open the '''geo '''file.
+| Now, in the terminal window, open the '''geo '''file.
 |-
 |  07:19
-| Now we have our geometry, we will do the meshing.
+| Now we have our geometry, we will do the '''meshing'''.
 |-
 | 07:23
-| '''Gmsh''' automaticaly generates the mesh of the defined geometry.
+| '''Gmsh''' automatically generates the mesh for the defined geometry.
 |-
@@ Line 282: / Line 280: @@
 |-
 | 07:48
-| We can also refine the mesh by clicking on the '''Refine by Splitting '''parameter in the mesh menu.
+| We can also refine the '''mesh''' by clicking on the '''Refine by Splitting '''parameter in the '''mesh''' menu.
 |-
 | 07:56
-| Now let us save our work.
+| Now, let us '''save''' our work.
 |-
 | 07:59
-| Go to '''File''' menu and click on '''Save as. '''
+| Go to '''File''' menu and click on '''Save as.'''
 |-
@@ Line 298: / Line 296: @@
 |-
 | 08:11
-| And type the name the file as '''aerofoil.msh'''
+| And type the name of the file as '''aerofoil.msh'''.
 |-
@@ Line 306: / Line 304: @@
 |-
 | 08:22
-| Click '''Ok ''' Again click '''Ok'''
+| Click '''OK '''. Again click '''OK'''.
 |-
@@ Line 314: / Line 312: @@
 |-
 | 08:29
-| As an '''assignment''' create another '''aerofoil''' by using different '''dat '''file for different '''aerofoil '''shapes.
+| As an assignment, create another '''aerofoil''' by using different '''dat '''file for different '''aerofoil '''shapes.
 |-
 |08:37
-| In this tutorial we learnt:
+| In this tutorial, we learnt:
-* How To create an aerofoil in Gmsh.
+* How to create an '''aerofoil''' in '''Gmsh'''.
-* How to do meshing in Gmsh
+* How to do '''meshing''' in '''Gmsh'''.
 |-
 | 08:45
-| Watch the video available at this URL:
+| Watch the video available at this URL.
 It summarizes the Spoken Tutorial project.
@@ Line 333: / Line 331: @@
 |-
 | 08:56
-| The Spoken Tutorial Project Team.Conducts workshops using spoken tutorials
+| The Spoken Tutorial Project team: Conducts workshops using spoken tutorials.
 |-
 | 09:00
-| Gives certificates to those who pass an online test
+| Gives certificates to those who pass an online test.
 |-
 | 09:03
-| For more details, please write to us contact@spoken-tutorial.org
+| For more details, please write to us at:
 |-
 | 09:06
-| Spoken Tutorials are part of Talk to a Teacher project,
+| '''Spoken Tutorials''' are part of '''Talk to a Teacher''' project.
 |-
@@ Line 353: / Line 352: @@
 |-
 | 09:15
-| More information on the same is available at the following URL link [http://spoken-tutorial.org/NMEICT-Intro http://spoken-tutorial.org/NMEICT-Intro]
+| More information on the same is available at the following URL:
 |-
 | 09:19
-| The script was written by Gautam Sharma and this is Rahul Joshi from IIT Bombay signing off. Thanks for joining.
+| The script was written by Gautam Sharma and this is Rahul Joshi from '''IIT Bombay''', signing off. Thanks for joining.
 |}