CFD Online Logo CFD Online URL
Home > Forums > FLUENT

Periodic flow

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

LinkBack Thread Tools Display Modes
Old   August 16, 2008, 02:59
Default Periodic flow
Posts: n/a
Dear Everyone:

I am trying to simulate the axial flow pump, and it can be treated as a periodic flow. My problem is that the flow rate using periodic flow is much lower that the result when I simulate the entire model. The MRF method is used. /grid/modify-zones/make-periodic is used to create the periodic. Pressure inlet and outlet are the boundary conditions. Different regions are connected with interface (Periodic).

Is there anyone familiar with this kind of model? Can you give me any suggestion to solve this problem? Is there anything else I forget to set up?

Thank you in advance
  Reply With Quote

Old   August 18, 2008, 12:24
Default Re: Periodic flow
Jason B
Posts: n/a
Periodic case will only report the flow rate through that one passage. You'll have to multiply it by the number of passages to get the proper flow rate (so if it's a 20 blade compressor, and you modeled one passage, your actual flow rate will be 20x the calculated flow rate).

If that's not the fix, then you'll have to spend some more time digging through your model. Checking pressure / mach contours on the compressor geometry. You're looking for major differences that you can then trace back to a cause (i.e. if you notice flow isn't moving from one passage to another, then it's a problem with your periodic BC... or if your static pressures are way different at the exit, then it could be your exit BC... stuff like that)

Hope this helps, Jason
  Reply With Quote


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
Periodic flow selim CFX 2 February 26, 2008 08:48
periodic boundaries - flow through a net PK FLUENT 0 July 12, 2007 11:58
periodic flow in 3D SAM FLUENT 0 October 11, 2006 18:19
periodic compressible flow vivian Main CFD Forum 2 April 25, 2006 05:04
periodic flow Grzegorz CFX 4 June 13, 2003 02:36

All times are GMT -4. The time now is 18:23.