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

Periodic boundary conditions for 2D pipe (water flow).

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

Like Tree3Likes
  • 1 Post By thess
  • 2 Post By A7A

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   May 31, 2012, 11:04
Default Periodic boundary conditions for 2D pipe (water flow).
  #1
New Member
 
Krzysztof
Join Date: May 2012
Posts: 7
Rep Power: 14
thess is on a distinguished road
Hello,
I'm an MSc student looking for an advice about periodic boundary conditions.

I've modelled 1 metre long pipe, 40mm diameter (see attached).

Boundary conditions defined in ICEMcfd were:
inlet - velocity inlet,
topwall - wall,
bottomwall - wall,
outlet - pressure outlet.
After loading model into fluent I've applied all necessary parameters like materials, BC's, methods and solver. Then I've performed test calculation to see if solution is converging - well it converged (after ~2000 iterations).
Next step is to change bc's into periodic. The goal is to get fully developed flow.

I've followed the instructions from fluent manual:
Quote:
> grid/modify-zones/make-periodic
Periodic zone [()] inlet
Shadow zone [()] outlet
Rotational periodic? (if no, translational) [yes] no
Create periodic zones? [yes] yes
Auto detect translation vector? [yes] yes
...
created periodic zones.
Then I've initialized solution again (using values computed earlier from inlet), and started calculations...

Well after 30000 iterations i still have no solution, and it does not seem to converge. I've tried different mesh densities but the problem still exist.

I'm not sure about my periodic boundaries implementation? Can anyone suggest me where the mistake is?

I'd appreciate anyhelp.

Regards.
Attached Images
File Type: jpg 29.05.jpg (45.9 KB, 117 views)
Keya likes this.
thess is offline   Reply With Quote

Old   May 31, 2012, 12:45
Default
  #2
A7A
Member
 
AHMAD
Join Date: Apr 2012
Posts: 54
Rep Power: 0
A7A is on a distinguished road
Hi,

Have you tried to increase the number of subiterations that been done on the pressure correction.
thess and Keya like this.
A7A is offline   Reply With Quote

Old   May 31, 2012, 13:54
Default
  #3
New Member
 
Krzysztof
Join Date: May 2012
Posts: 7
Rep Power: 14
thess is on a distinguished road
Hello,

Thanks for the reply.

I changed it, simulation is running. But so far I haven't noticed any difference. Well, I'll give it some time.
But I'm afraid it wont solve my problem
thess is offline   Reply With Quote

Old   May 31, 2012, 14:38
Default
  #4
A7A
Member
 
AHMAD
Join Date: Apr 2012
Posts: 54
Rep Power: 0
A7A is on a distinguished road
If it doesnt work, try to make your mesh using ANSYS standard mesher.
A7A is offline   Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Water subcooled boiling Attesz CFX 7 January 5, 2013 04:32
error message cuteapathy CFX 14 March 20, 2012 07:45
Please help with flow around car modelling! Tudor Miron CFX 17 March 19, 2004 20:23
Pipe Flow Boundary conditions Kunal Jain Main CFD Forum 0 September 4, 2001 21:52


All times are GMT -4. The time now is 12:44.