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

How to specify an inlet boundary conditions for a fully developed gas flow in a duct.

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

Like Tree2Likes
  • 1 Post By legendyxg
  • 1 Post By leonardo.morita

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   May 11, 2010, 04:08
Default How to specify an inlet boundary conditions for a fully developed gas flow in a duct.
  #1
New Member
 
Yang Xiaoguang
Join Date: Apr 2009
Posts: 24
Rep Power: 17
legendyxg is on a distinguished road
Dear everyone,

My model contains a rectangular duct with various kinds of gases flow through it. What I care is only the fully-developed region while I only know the mass flow rate. I found that if I specify the inlet boundary as a mass-flow-inlet type, the inlet region is not fully developed. So what kind of boundary type should I use in order to avoid the inlet developing length?

Thank you.
CFD_beginner12 likes this.
legendyxg is offline   Reply With Quote

Old   May 11, 2010, 05:30
Default
  #2
Member
 
Leonardo Giampani Morita
Join Date: Apr 2009
Location: Paris, France
Posts: 58
Rep Power: 17
leonardo.morita is on a distinguished road
Hello,
If you want a fully developed flow at inlet, you should firstly run another simulation, in which you impose periodic conditions or you have a sufficiently long developing region. Once you obtain a developed flow at the outlet of this system, you can write a profile (Write > Profile) for your velocity and then read it in your final case (Read > Profile). When setting boundary conditions, you'll see that this profile will be available ("constant" tab). See FLUENT User's Guide chapter 4.6 for some more details.
CFD_beginner12 likes this.
leonardo.morita is offline   Reply With Quote

Old   May 11, 2010, 07:32
Default
  #3
New Member
 
Yang Xiaoguang
Join Date: Apr 2009
Posts: 24
Rep Power: 17
legendyxg is on a distinguished road
I'll have a try and thanks for your help.
legendyxg 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
Boundary conditions for 2phase countercurrent flow rakib FLUENT 5 September 2, 2011 08:14
Proper Pressure Boundary Conditions for Buoyant Flow mchurchf OpenFOAM 0 March 25, 2010 12:16
RPM in Wind Turbine Pankaj CFX 9 November 23, 2009 04:05
Fully Developed Boundary Condition at Duct Inlet Twiti CFX 1 January 24, 2005 01:31
Boundary Conditions Jan Ramboer Main CFD Forum 11 August 16, 1999 08:59


All times are GMT -4. The time now is 07:38.