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

Confused about periodic interface

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

Reply
 
LinkBack Thread Tools Display Modes
Old   July 24, 2012, 21:41
Default Confused about periodic interface
  #1
New Member
 
Join Date: Jul 2012
Posts: 2
Rep Power: 0
Jeff is on a distinguished road
I think I have an easy question, but am confused about setting the correct boundaries/interfaces.

I want to model an infinite pipe. I have modeled a pipe with inlet face, outlet face and side walls. I select the inlet and outlet faces and make an in-place interface. So now I have an additional interface line item under the regions section, and also a periodic interface under the interface item.

Under the periodic interface of the interface line item I change it to fully developed. There is also an option here to specify mass flow rate-- i do this since this is what I know.

My question is the original boundaries in the region. While making the interface inserted an interface line item in the faces section of the region, there are still the original faces of the boundaries. I had already defined the inlet as a mass inlet and the outlet as a flow split outlet-- do I keep them as these (even since now they are part of an interface)? Then under the mass inlet I can specify a mass flow rate-- but what is determinig the flow-- this flow rate or the one I specified under the interface line item? If I change the inlet face to a velocity face and set that-- does that control the flow?

Is this the proper method? When I run it my velocity drops. It seems like the specific mass flowrate is not being implemented.

Thanks for your help. I'm just confused because the boundaries plus the additional interfaces seem to overspecify the problem-- though neither really seem to be implemented in the problem.
Jeff is offline   Reply With Quote

Old   July 26, 2012, 03:14
Default
  #2
New Member
 
Join Date: Jul 2012
Posts: 2
Rep Power: 0
Jeff is on a distinguished road
Nevemind. I think I was having a different problem. I implemented it with a mass inlet and flow split outlet. And it apears the the flowrate is controlled under the interface item, and not that in the mass flow inlet item.
Jeff is offline   Reply With Quote

Old   July 28, 2012, 05:38
Default
  #3
Senior Member
 
Join Date: Oct 2009
Location: Germany
Posts: 637
Rep Power: 12
abdul099 is on a distinguished road
Right, otherwise it wouldn't make much sense.
The only thing to know, what you missed so far, is: When you have an interface, all faces which can be matched with the opposite site of the interface, will be moved from the inlet / outlet / whatever boundary to the interface boundary.
You should keep the original boundary, but it will have no effect since it will be empty and all faces will be in the interface boundary. Of couse, this is only true as long as you can have a 100% matching, so the boundaries used to create the interface need to have the same shape and size.
__________________
We do three types of jobs here:
GOOD, FAST AND CHEAP
You may choose any two!
abdul099 is offline   Reply With Quote

Old   August 15, 2012, 22:30
Default
  #4
New Member
 
saleh
Join Date: Aug 2012
Posts: 25
Rep Power: 4
saleh alsubari is on a distinguished road
Dear friends , why during running the simulation , errors says full develop interface must has no inlet and out let.. what does that mean?

thanx
saleh alsubari is offline   Reply With Quote

Reply

Tags
interface, periodic

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
Wind turbine simulation Saturn CFX 34 October 16, 2014 05:27
RPM in Wind Turbine Pankaj CFX 9 November 23, 2009 05:05
confused by "periodic Non-Conformal Grids" turbinesv FLUENT 1 February 12, 2009 10:00
Convective Heat Transfer - Heat Exchanger Mark CFX 6 November 15, 2004 16:55
Replace periodic by inlet-outlet pair lego CFX 3 November 5, 2002 21:09


All times are GMT -4. The time now is 01:52.