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

How to define 2 grids to move the inner object?

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

Reply
 
LinkBack Thread Tools Display Modes
Old   April 12, 2011, 08:09
Default How to define 2 grids to move the inner object?
  #1
New Member
 
Hans Johans
Join Date: Apr 2011
Posts: 6
Rep Power: 6
lepetitmort is on a distinguished road
problem description:

I want to simulate a case with a moving object.
Can somebody help me and give some ideas for the principal approach.



It should be similar to this project
http://www.youtube.com/watch?v=S-p0uau9nGA

I would solve it in this way:

1. Design the grid of the big rectangle (with a rectangle-shaped hole in the middle)


2. Design grid of the small rectangle with the object in the middle
3. Write a UDF for movement
4. Use the fluent funktion to reshape the grid during the simulation. (dynamic meshing)


My questions:

1. Do I have to divide the 2 rectangles in the mesher or in the geometry-builder?
When I use the Designmodeler, draw the 2 rectangle and the object, click then on "surface from sketches", the space between inner rectangle and circle is empty. And I don't know how to avoid that. Some Ideas?

2. Are there any faults in my plan?
3. Any suggestions to improve it?

Last edited by lepetitmort; April 12, 2011 at 11:21.
lepetitmort is offline   Reply With Quote

Old   April 13, 2011, 12:05
Default
  #2
Senior Member
 
PSYMN's Avatar
 
Simon Pereira
Join Date: Mar 2009
Location: Ann Arbor, MI
Posts: 2,662
Blog Entries: 1
Rep Power: 35
PSYMN has a spectacular aura aboutPSYMN has a spectacular aura about
These are separate overlapping grids? I have never actually solved one of these, but I would guess that you probably need to mesh them separately, not as a single model. Then overlap the mesh models in the solver.
__________________
-----------------------------------------
Please help guide development at ANSYS by filling in these surveys

Public ANSYS ICEM CFD Users Survey

This second one is more general (Gambit, TGrid and ANSYS Meshing users welcome)...

CFD Online Users Survey
PSYMN is offline   Reply With Quote

Old   April 16, 2011, 08:01
Default
  #3
New Member
 
Hans Johans
Join Date: Apr 2011
Posts: 6
Rep Power: 6
lepetitmort is on a distinguished road
The trick is
1. to make TWO sketches.
2. splitface
lepetitmort is offline   Reply With Quote

Old   April 16, 2011, 11:05
Default
  #4
Senior Member
 
PSYMN's Avatar
 
Simon Pereira
Join Date: Mar 2009
Location: Ann Arbor, MI
Posts: 2,662
Blog Entries: 1
Rep Power: 35
PSYMN has a spectacular aura aboutPSYMN has a spectacular aura about
That will get you your nested box structure, but won't allow the one mesh to fall thru the other... Or do you mean to morph th outer box?

Sorry, I thought you planned for overlapping grids.
__________________
-----------------------------------------
Please help guide development at ANSYS by filling in these surveys

Public ANSYS ICEM CFD Users Survey

This second one is more general (Gambit, TGrid and ANSYS Meshing users welcome)...

CFD Online Users Survey
PSYMN is offline   Reply With Quote

Old   June 30, 2011, 11:38
Default mesh morphing
  #5
meb
Member
 
Marco Evangelos Biancolini
Join Date: May 2009
Location: Rome - Italy
Posts: 77
Rep Power: 8
meb is on a distinguished road
I think that the problem can be faced using the mesh morphing tool RBF Morph (www.rbf-morph.com).

meb is offline   Reply With Quote

Old   July 1, 2011, 15:58
Default
  #6
Senior Member
 
PSYMN's Avatar
 
Simon Pereira
Join Date: Mar 2009
Location: Ann Arbor, MI
Posts: 2,662
Blog Entries: 1
Rep Power: 35
PSYMN has a spectacular aura aboutPSYMN has a spectacular aura about
I have looked at a variety of morphing tools and none are more powerful or better integrated into Fluent than RBF-Morph...

Simon
__________________
-----------------------------------------
Please help guide development at ANSYS by filling in these surveys

Public ANSYS ICEM CFD Users Survey

This second one is more general (Gambit, TGrid and ANSYS Meshing users welcome)...

CFD Online Users Survey
PSYMN 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
Installing OF 1.6 on Mac OS X gschaider OpenFOAM Installation 140 June 19, 2010 09:23
Compilation error OF1.5-dev on Suse10.3 darenyang OpenFOAM Installation 0 April 29, 2009 04:55
Missing math.h header Travis FLUENT 4 January 15, 2009 12:48
Free surface boudary conditions with SOLA-VOF Fan Main CFD Forum 10 September 9, 2006 12:24
UDF FOR UNSTEADY TIME STEP mayur FLUENT 3 August 9, 2006 10:19


All times are GMT -4. The time now is 20:36.