CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Mesh Generation & Pre-Processing

mesh generation for wind tunnel

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Display Modes
Old   March 8, 2013, 20:24
Default mesh generation for wind tunnel
  #1
New Member
 
Waleed
Join Date: Feb 2013
Posts: 8
Rep Power: 4
Waleedooo is on a distinguished road
Dear friends, I'm asking all of you to help me in this problem

first i'm going to represent the wind tunnel in fluent so i have to prepare the model first and i want to use a size function with a boundary layer to make the mesh too smooth over the building faces and going with a good grading until reaching the tunnel walls and become coarse, and my questions are:

1- when defining the size function I'm choosing the building faces as sources and the domain flow or the air domain as the attachment, so is that correct???

2- when defining the boundary layer I'm choosing the 5 faces of my building as the attachment but when I'm checking the shape of the layer i found it coming over the tunnel bottom only or the grading coming over the surface of the tunnel bottom only, so how i can solve this problem to see the grading coming around my building and starting from the building faces smooth and going coarse away from the building faces?


the attached file is for my model, so could any body helping me because this is too much urgent for me in my study, thank you very much my friend and looking for your cooperation, bye bye
Attached Files
File Type: zip trial of Domain A.zip (2.5 KB, 22 views)
Waleedooo is offline   Reply With Quote

Old   March 11, 2013, 07:17
Default
  #2
Super Moderator
 
-mAx-'s Avatar
 
Maxime Perelli
Join Date: Mar 2009
Location: Switzerland
Posts: 2,961
Rep Power: 30
-mAx- will become famous soon enough
1- yes
2- I cannot open your zip file
__________________
In memory of my friend Hervé: CFD engineer & freerider
-mAx- is online now   Reply With Quote

Old   March 11, 2013, 16:48
Default
  #3
New Member
 
Waleed
Join Date: Feb 2013
Posts: 8
Rep Power: 4
Waleedooo is on a distinguished road
My Friend I think it a *rar file not a zip file so please try to open it with winrar, thank you very much for your cooperation,

Waleed
Waleedooo is offline   Reply With Quote

Old   March 12, 2013, 08:29
Default
  #4
Super Moderator
 
-mAx-'s Avatar
 
Maxime Perelli
Join Date: Mar 2009
Location: Switzerland
Posts: 2,961
Rep Power: 30
-mAx- will become famous soon enough
before applying size function, set your BL on your walls.
__________________
In memory of my friend Hervé: CFD engineer & freerider
-mAx- is online now   Reply With Quote

Old   March 12, 2013, 16:21
Default
  #5
New Member
 
Waleed
Join Date: Feb 2013
Posts: 8
Rep Power: 4
Waleedooo is on a distinguished road
I tried to do that many times but its not working, could you explain in a steps the setting boundary layers and the size function, thank you
Waleedooo is offline   Reply With Quote

Old   March 13, 2013, 03:00
Default
  #6
Super Moderator
 
-mAx-'s Avatar
 
Maxime Perelli
Join Date: Mar 2009
Location: Switzerland
Posts: 2,961
Rep Power: 30
-mAx- will become famous soon enough
-import your .sat file.
-go to BL panel, switch to faces (Attachmane), and select faces on which you want to apply BL.
-Enable internal continuity and wedge corner shape
-set first row and if desire increase Rows number (and/or growth factor)

-Then go to Size Function, in Source switch to surfaces and select the surfaces which will be fine meshed, and choose attachmen (in your case your volume). Start size is your minimal celll size, then growth rate (1.2 for example, and your max size.
__________________
In memory of my friend Hervé: CFD engineer & freerider
-mAx- is online now   Reply With Quote

Old   March 13, 2013, 11:55
Default
  #7
New Member
 
Waleed
Join Date: Feb 2013
Posts: 8
Rep Power: 4
Waleedooo is on a distinguished road
Thank you very much my friend, I'll try it and I'll tell you whats happen with me, thank you very much
Waleedooo is offline   Reply With Quote

Old   March 17, 2013, 19:11
Default
  #8
New Member
 
Waleed
Join Date: Feb 2013
Posts: 8
Rep Power: 4
Waleedooo is on a distinguished road
Dear Friend,

I did exactly what you said and I generate the mesh and its the same as what I did before, the mesh coming smooth on the tunnel bottom only and the faces of the building but for the volume coming coarse and I'm still confused because I'm feeling that the transition from coarse volume cells to the smooth faces cells will not give an accurate results, I did the following
1- creating the B.L. and I choose the 5 faces of the building and first/last aspect was 3 and the number of rows =12 the sources as I said 5 faces of the internal building then ok
2- the second step is defining the size function and its starting from faces and the attachment is the volume
3- meshing using tetrahedral/ t-grid


Could you tell me if I did somthing wrong or could you try it, thank you

Waleed
Waleedooo is offline   Reply With Quote

Old   March 18, 2013, 04:15
Default
  #9
Super Moderator
 
-mAx-'s Avatar
 
Maxime Perelli
Join Date: Mar 2009
Location: Switzerland
Posts: 2,961
Rep Power: 30
-mAx- will become famous soon enough
display picture of your mesh: go to examine mesh, and choose "cut".
Display a cut in the middle, to see what sounds weird according to you
__________________
In memory of my friend Hervé: CFD engineer & freerider
-mAx- is online now   Reply With Quote

Old   March 18, 2013, 11:24
Default
  #10
New Member
 
Waleed
Join Date: Feb 2013
Posts: 8
Rep Power: 4
Waleedooo is on a distinguished road
Hi,
my friend please check the atachements here, you will find 2 images the first one is from outside the cube and not represent the real mesh but when I did the cut as you said its coming different, oh my God is the internal cut reprenst the real mesh or not, I spent more that a month now with this issue and you guided me to the internal cut plane, so is what I did with this mesh correct or not

thank you very much for the advices and waiting for your reply, thanks again
Attached Images
File Type: jpg 3-18-2013 5-53-55 PM.jpg (103.2 KB, 37 views)
File Type: jpg 3-18-2013 6-16-46 PM.jpg (103.7 KB, 30 views)
Waleedooo is offline   Reply With Quote

Old   March 19, 2013, 03:08
Default
  #11
Super Moderator
 
-mAx-'s Avatar
 
Maxime Perelli
Join Date: Mar 2009
Location: Switzerland
Posts: 2,961
Rep Power: 30
-mAx- will become famous soon enough
yes second is your real mesh (you see what's append inside your domain)
on your first picture you only see boundary mesh
From second picture you can see the size function: mesh is fine on your cube and is growing
__________________
In memory of my friend Hervé: CFD engineer & freerider
-mAx- is online now   Reply With Quote

Old   March 19, 2013, 19:36
Default Thank you
  #12
New Member
 
Waleed
Join Date: Feb 2013
Posts: 8
Rep Power: 4
Waleedooo is on a distinguished road
Dear friend ,

I appreciate what you did with me, Thank you Very much

Waleed
Waleedooo is offline   Reply With Quote

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
[ICEM] Generating Mesh for STL Car in Windtunnel Simulation tommymoose ANSYS Meshing & Geometry 48 April 15, 2013 04:24
No layers in a small gap bobburnquist OpenFOAM Native Meshers: snappyHexMesh and Others 2 November 25, 2012 09:54
2D Mesh Generation Tutorial for GMSH aeroslacker Open Source Meshers: Gmsh, Netgen, CGNS, ... 12 January 19, 2012 04:52
Mesh generation software is needed H.Dou Main CFD Forum 12 May 4, 2011 15:20
Convergence moving mesh lr103476 OpenFOAM Running, Solving & CFD 30 November 19, 2007 15:09


All times are GMT -4. The time now is 01:29.