CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > ANSYS Meshing & Geometry

[GAMBIT] problems in boundary layer

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   April 18, 2010, 03:32
Default problems in boundary layer
  #1
Member
 
李逾
Join Date: Mar 2010
Posts: 65
Rep Power: 16
yubaibai88 is on a distinguished road
dear all:
I'm new in gambit and recently I am going through the gambit modeling guide for study.but met some problems unable to work out about boundary layer.

first I creat a rectangle.then creat boundary layers in the bottom and right edge.shown in picture 1.

then I mesh the rectangle with QUAD/MAP scheme,and 0.1 interval size.
shown in picture 2.

I want to change the verticle type in buttom-right corner into side.but gain the same result in both unable/disable Boundary layer only option.shown in picture 3.

here is my problem:
1.what does boundary layer do in meshing process.or what effect it has on my meshing result after QUAD/MAP mesh in the rectangle.

2.how could I change the vertex type in meshing.in SET FACE VERTEX TPYES option,I have no choice to determin the domain in which the vertex type could be change(meshing or boundary layer characteristic).

thanks in advance!
Attached Images
File Type: jpg 1.JPG (23.7 KB, 38 views)
File Type: jpg 2.JPG (97.2 KB, 33 views)
File Type: jpg 3.jpg (100.0 KB, 38 views)

Last edited by yubaibai88; April 18, 2010 at 03:56.
yubaibai88 is offline   Reply With Quote

Old   April 19, 2010, 03:40
Default
  #2
Super Moderator
 
-mAx-'s Avatar
 
Maxime Perelli
Join Date: Mar 2009
Location: Switzerland
Posts: 3,297
Rep Power: 41
-mAx- will become famous soon enough
once you modified your Vertex type(enable "BL only") (and also the BL), delete the face mesh, and remesh the face.
The surface mesh won't be updated if you modify one of it's BL
__________________
In memory of my friend Hervé: CFD engineer & freerider
-mAx- is offline   Reply With Quote

Old   April 19, 2010, 09:36
Default
  #3
Member
 
李逾
Join Date: Mar 2010
Posts: 65
Rep Power: 16
yubaibai88 is on a distinguished road
Quote:
Originally Posted by -mAx- View Post
once you modified your Vertex type(enable "BL only") (and also the BL), delete the face mesh, and remesh the face.
The surface mesh won't be updated if you modify one of it's BL
hi mAx:
thanks for your advance.

can you tell me what are the diffenentials/relationship between boudary layers and face meshing.

I mesh the face after creat boundarys along the edge.but as I see there are no association between them.

thank you!
yubaibai88 is offline   Reply With Quote

Old   April 19, 2010, 10:20
Default
  #4
Super Moderator
 
-mAx-'s Avatar
 
Maxime Perelli
Join Date: Mar 2009
Location: Switzerland
Posts: 3,297
Rep Power: 41
-mAx- will become famous soon enough
Face mesh should be attached to your BL.
Post a picture of what you get (-->" no association between them")
__________________
In memory of my friend Hervé: CFD engineer & freerider
-mAx- is offline   Reply With Quote

Old   April 19, 2010, 10:43
Default
  #5
Member
 
李逾
Join Date: Mar 2010
Posts: 65
Rep Power: 16
yubaibai88 is on a distinguished road
Quote:
Originally Posted by -mAx- View Post
Face mesh should be attached to your BL.
Post a picture of what you get (-->" no association between them")
hi mAx:
thanks for your advances!

here is where my problem come from:

1.I draw a square the side of which is 5.

2.mesh the bottom and right edge with interval count 5.

3.creat boundary layers on the edge meshed in step 2. then I gained image shown in picture 1.

4.then I meshed the face with QUAD/MAP scheme with interval size 1.gained image shown in picture 2.
as you see in picture 2,the face mesh and boundary seem as if they are coincide.

5.it goes without saying that the type of four vertexs on the face are END.now I change the type of button-right corner vertex to SIDE.it gained the image shown in picture 3.

you can see the bounday layers distort and boundary layers remains prior shape.
can you tell me why they perform like this.if the face mesh attach to boundary layer,why it doesn't change shape while boundary layers distort.

thanks you!
Attached Images
File Type: jpg 1.JPG (18.6 KB, 16 views)
File Type: jpg 2.JPG (24.0 KB, 19 views)
File Type: jpg 3.JPG (28.8 KB, 25 views)
yubaibai88 is offline   Reply With Quote

Old   April 19, 2010, 10:54
Default
  #6
Super Moderator
 
-mAx-'s Avatar
 
Maxime Perelli
Join Date: Mar 2009
Location: Switzerland
Posts: 3,297
Rep Power: 41
-mAx- will become famous soon enough
at point5: delete the mesh, and remesh the face. Gambit will take the new BL in count
__________________
In memory of my friend Hervé: CFD engineer & freerider
-mAx- is offline   Reply With Quote

Old   April 19, 2010, 11:12
Default
  #7
Member
 
李逾
Join Date: Mar 2010
Posts: 65
Rep Power: 16
yubaibai88 is on a distinguished road
Quote:
Originally Posted by -mAx- View Post
at point5: delete the mesh, and remesh the face. Gambit will take the new BL in count
hi:
I solve it,gained the picture 1.and after I hide the boundary gained picture 2.
thank you very much!
Attached Images
File Type: jpg 1.JPG (57.7 KB, 17 views)
File Type: jpg 2.JPG (51.8 KB, 19 views)
yubaibai88 is offline   Reply With Quote

Old   April 19, 2010, 13:55
Default
  #8
Super Moderator
 
-mAx-'s Avatar
 
Maxime Perelli
Join Date: Mar 2009
Location: Switzerland
Posts: 3,297
Rep Power: 41
-mAx- will become famous soon enough
while changing vertex type, enable "BL only". Thus you will still be able to mesh the face with map schema (because in the face the vertex will still have a End value). In your case, you cannot anymore, that's why you get a mesh with pave schema
__________________
In memory of my friend Hervé: CFD engineer & freerider
-mAx- is offline   Reply With Quote

Old   April 19, 2010, 22:07
Default
  #9
Member
 
李逾
Join Date: Mar 2010
Posts: 65
Rep Power: 16
yubaibai88 is on a distinguished road
Quote:
Originally Posted by -mAx- View Post
while changing vertex type, enable "BL only". Thus you will still be able to mesh the face with map schema (because in the face the vertex will still have a End value). In your case, you cannot anymore, that's why you get a mesh with pave schema
hi mAx:

as you say,I trid again by enable 'boundary layer only',gained image shown in picture 1.that's what I want!

thank you!
Attached Images
File Type: jpg 1.JPG (46.9 KB, 22 views)
yubaibai88 is offline   Reply With Quote

Reply


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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Turbulent Boundary Layer on a Flat Plate Hoshang Garda FLUENT 1 November 27, 2013 11:24
Combining BCs: wall - outlet. Boundary layer disappears MartinaF OpenFOAM Running, Solving & CFD 1 July 20, 2009 19:14
Boundary Layer mahadevan.swamy FLUENT 1 June 29, 2009 09:10
GAMBIT problem with 3D Boundary Layer when meshing Anthony Haroutunian FLUENT 2 March 26, 2008 03:02
Please help with flow around car modelling! Tudor Miron CFX 17 March 19, 2004 20:23


All times are GMT -4. The time now is 01:25.