CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > CFX

Cylindrical Symmetry

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

Reply
 
LinkBack Thread Tools Display Modes
Old   September 21, 2012, 11:07
Default Cylindrical Symmetry
  #1
New Member
 
Vikram Reddy
Join Date: Jun 2012
Posts: 13
Rep Power: 5
VikramR is on a distinguished road
Hello CFX users, I have a reactor with cylindrical symmetry. How do I solve the problem on only one plane of theta?. I know this is to be done using slice material but when I slice an arc that does not form from the center of the cylinder.
Please help.
VikramR is offline   Reply With Quote

Old   September 21, 2012, 11:30
Default
  #2
New Member
 
Dustin
Join Date: Jan 2012
Posts: 18
Rep Power: 5
Trues is on a distinguished road
what program was used to make the geometry? Do you have the ability to modify that geometry, or was it given to you?

For me, if it was given to me as a full cylinder (for example) in ProE, I'd much rather make the cyclic cut in ProE than in DesignModeler
Trues is offline   Reply With Quote

Old   September 21, 2012, 11:52
Default
  #3
New Member
 
Vikram Reddy
Join Date: Jun 2012
Posts: 13
Rep Power: 5
VikramR is on a distinguished road
Thanks for the reply.
I made the geometry myself in DesignModeler
VikramR is offline   Reply With Quote

Old   September 21, 2012, 13:48
Default
  #4
New Member
 
Dustin
Join Date: Jan 2012
Posts: 18
Rep Power: 5
Trues is on a distinguished road
A picture would speak 1000 words.

If I'm picturing your issue correctly, which it's possible I'm not, you're having trouble getting the slice to go through the centerline of the cylinder? Why don't you add a new coordinate system at the centerline on the face of your cylindrical geometry and sketch your slice so that you can constrain it to the geometry centerline?
Trues is offline   Reply With Quote

Old   September 21, 2012, 13:52
Default
  #5
New Member
 
Vikram Reddy
Join Date: Jun 2012
Posts: 13
Rep Power: 5
VikramR is on a distinguished road
In the sliced material, when I give the inward thickness on extrude to be less than 2 cm( which is the radius of the cylinder), it accepts. But when I want it to be 2cm it wont accept the value. Does it make more sense now?
VikramR is offline   Reply With Quote

Old   September 21, 2012, 13:56
Default
  #6
New Member
 
Dustin
Join Date: Jan 2012
Posts: 18
Rep Power: 5
Trues is on a distinguished road
sounds like you're trying to slice a wedge out of your cylinder, right? Your sketch needs to be opened. Don't draw the arc, just the two radials, like an open V. Is this what you're having trouble with?
Trues is offline   Reply With Quote

Old   September 21, 2012, 14:00
Default
  #7
New Member
 
Vikram Reddy
Join Date: Jun 2012
Posts: 13
Rep Power: 5
VikramR is on a distinguished road
Yeah, you figured it out right but,
I could draw the outer edge but not the one closer to the center i.e, i can not draw the sharp edge.
VikramR is offline   Reply With Quote

Old   September 21, 2012, 14:11
Default
  #8
New Member
 
Dustin
Join Date: Jan 2012
Posts: 18
Rep Power: 5
Trues is on a distinguished road
The only other thing i can say is try with thin surface set as no. I'd have to see what you're talking about to help any further
Trues is offline   Reply With Quote

Old   September 21, 2012, 19:44
Default
  #9
Senior Member
 
Erik
Join Date: Feb 2011
Location: Earth (Land portion)
Posts: 486
Rep Power: 9
evcelica is on a distinguished road
Dont slice or cut your geometry. Just use TOOLS > SYMMETRY. Set to two planes, have one plane be whatever plane cuts through the center, and create another plane rotated 1 degrees or so off that one.
evcelica is offline   Reply With Quote

Old   September 24, 2012, 20:12
Default
  #10
New Member
 
Vikram Reddy
Join Date: Jun 2012
Posts: 13
Rep Power: 5
VikramR is on a distinguished road
Thank you very much, I used symmetry and it worked perfectly.
VikramR is offline   Reply With Quote

Old   September 25, 2012, 03:43
Default
  #11
Senior Member
 
Erik
Join Date: Feb 2011
Location: Earth (Land portion)
Posts: 486
Rep Power: 9
evcelica is on a distinguished road
No problem. Yeah, the symmetry tool works very well for symmetry
evcelica is offline   Reply With Quote

Old   September 25, 2012, 06:50
Default
  #12
Senior Member
 
Bruno
Join Date: Mar 2009
Location: Brazil
Posts: 236
Rep Power: 12
brunoc is on a distinguished road
Also, remember to set periodicity in ANSYS Meshing so that you get a 1:1 mesh connection when setting your periodic BCs in CFX. GGI interfaces do work pretty well, but by using a 1:1 interface you save memory and CPU time.

Cheers
brunoc is offline   Reply With Quote

Old   September 25, 2012, 08:03
Default
  #13
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 10,646
Rep Power: 84
ghorrocks has a spectacular aura aboutghorrocks has a spectacular aura aboutghorrocks has a spectacular aura about
If the simulation has no swirl then use symmetry planes on the top and bottom faces. If the simulation has swirl then use periodic boundaries.

BTW: This thread is an FAQ - http://www.cfd-online.com/Wiki/Ansys..._simulation.3F

You might as well just point people to the FAQ. If you think the FAQ is wrong or could be improved then feel free to edit it.
ghorrocks 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
View factor radiation model. Symmetry boundaries verification.. Dimoon OpenFOAM Running, Solving & CFD 9 April 29, 2014 02:12
[ICEM] Blocking and Symmetry BrolY ANSYS Meshing & Geometry 32 August 24, 2012 03:13
stressedFoam with wall motion looses symmetry and does not converge gtg258f OpenFOAM 1 June 6, 2012 12:28
Properly using symmetry with both CFX and ANSYS workbench for a FSI analysis, help! Cirion0000 CFX 0 July 6, 2009 14:26
Forces in Symmetry Matt CFX 2 February 25, 2009 06:41


All times are GMT -4. The time now is 05:14.