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

[GAMBIT] meshing of wavy fins

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   January 29, 2011, 20:59
Unhappy meshing of wavy fins
  #1
New Member
 
Diala
Join Date: Dec 2010
Posts: 8
Rep Power: 16
dldl is on a distinguished road
Hi
I would model a heat exchanger with finned wavy fins. I drew the model in Gambit and wanted to mesh the model. I meshed the four pipes as the following:
-Mesh face scheme for the Fin-Tube: Quad – Map
-Mesh volume ccheme: Hex/Wedge – Cooper
I then tried to mesh the other volume with “Hex/Wedge – Cooper” But a problem always happens when I mesh Volume 3.
I tried later to mesh the volume 1 and 2 with “Hex/Wedge – Cooper” and the volume 3 with the scheme “T grid” but the problem has remained.
Can someone help me how I can mesh the volume 1, 2 and 3 without errors.
Thanks
Attached Images
File Type: jpg finned tube.jpg (40.2 KB, 64 views)
File Type: jpg model1.jpg (10.9 KB, 38 views)
dldl is offline   Reply With Quote

Old   January 31, 2011, 02:49
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
I don't understand the difference between volumes 1,2 and 3
As I understand, you have 4 pipes (annular pipe), and the other volume (the wavy one)
__________________
In memory of my friend Hervé: CFD engineer & freerider
-mAx- is offline   Reply With Quote

Old   January 31, 2011, 04:57
Default
  #3
New Member
 
Diala
Join Date: Dec 2010
Posts: 8
Rep Power: 16
dldl is on a distinguished road
Thanks Mr. Max
I apologize that my English is poor.

Iat the beginning drew 3 volumes. Volume 1 is the half thickness of fin1.
Volume 2 is the half thickness of fin2
Volume 3 is the gap between the two fins 1 and 2
These three volumes are connected and can be merged. I believe, however, that is not necessary!
the others volumes are annual pipes.
(if you can german, we can write in german)
dldl is offline   Reply With Quote

Old   January 31, 2011, 05:00
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
Can you post a picture where we can see volumes 1,2 and 3
Yes I can german, but since the thread could be usefull for anyone else, it is better to continue in english.
If I don't understand your english, I will send you a private message in german
__________________
In memory of my friend Hervé: CFD engineer & freerider
-mAx- is offline   Reply With Quote

Old   January 31, 2011, 05:39
Default
  #5
New Member
 
Diala
Join Date: Dec 2010
Posts: 8
Rep Power: 16
dldl is on a distinguished road
If the arc is not so long and the curve is not so great, I can mesh the model simply that the volume 1 and 2 with Scheme "Cooper" and Volume 3 with T- Grid.
Attached Images
File Type: jpg modell ohne Mesh.jpg (63.6 KB, 27 views)
dldl is offline   Reply With Quote

Old   February 1, 2011, 03:50
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
ok,
I saw your dbs file.
You sent me 2 versions, but you have to work with the second: the one with all the surfaces and edges merged.
It will avoid high skewness in your mesh, and it will make all volumes meshable with hex-cooper (automatically selected from Gambit).
This is exactly your second dbs file (arc3h11)
Now there is a problem while meshing. With my computer, you can mesh one volume, then the other makes the meshing prozess to be frozen.
Just for checking, if you merge all the volumes, then this problem disappear.
That mean the problem should come from the wavy and thin volume.
There is a workaround:
you need to split all your volumes for avoiding wavy extrusion in subvolume.
Doing this you can then mesh all your volumes directly with hexa.
Another advantage, is that you will have more control on your mesh and you will be able to refine the subvolumes with less effort from your hardware.
Since your dbs file is already made from virtual volumes, for splitting you need to:
*split edges >> vertex generated
*split surface from vertices >> edges liying on the surface is generated (edge is a split of your surface)
*creating wireframe surface from edges
*split your volume with the surface
Sans titre.jpg
__________________
In memory of my friend Hervé: CFD engineer & freerider
-mAx- is offline   Reply With Quote

Old   February 1, 2011, 04:07
Default
  #7
New Member
 
Diala
Join Date: Dec 2010
Posts: 8
Rep Power: 16
dldl is on a distinguished road
Thanks
I will follow these steps.
dldl is offline   Reply With Quote

Old   February 1, 2011, 06:18
Default
  #8
New Member
 
Diala
Join Date: Dec 2010
Posts: 8
Rep Power: 16
dldl is on a distinguished road
I have a question about boundary conditions:
How to determine the BC for the lower and upper faces of Fins?
The following is known:
-Water temperature through pipes is 308 k
-Temperature of the air (inlet) is 293 k
I mean here the thermal condition!
dldl is offline   Reply With Quote

Old   February 18, 2015, 14:10
Default
  #9
New Member
 
Join Date: Feb 2015
Posts: 2
Rep Power: 0
ArunPrasanth is on a distinguished road
So you are saying that each part should be meshed separately ??
ArunPrasanth is offline   Reply With Quote

Reply

Tags
heat exchanger, mesh gambit, wavy fins


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
[GAMBIT] Desperate student needs help meshing 3D GAMBIT model - please help! lau06165 ANSYS Meshing & Geometry 1 March 22, 2010 02:09
Best Meshing scheme for Cylinder Nutrex Main CFD Forum 4 July 29, 2008 12:03
Meshing locks workbench window. andy2o CFX 0 February 1, 2008 06:01
Singularity of grid?Volume meshing vs face meshing Ken Main CFD Forum 0 September 4, 2003 12:09
Volume Meshing & Face Meshing? singularity of grid ken FLUENT 0 September 4, 2003 12:08


All times are GMT -4. The time now is 15:14.