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

Outlet velocity boundary condition

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   December 11, 2002, 07:36
Default Outlet velocity boundary condition
  #1
Jay
Guest
 
Posts: n/a
Hi there I am trying to use outlet velocity BC for my ASMM in Fluent 6. In my model, I have one inlet and two outlets BC. I have to maintain a ratio between these two outlets. I can use negative flow velocity BC for one outlet and pressure outlet for other. However I have to specify the volume fraction at the outlet velocity BC. But I do not have the value. Is there anyway to specify outlet flow velocity condition.

Thanks for your help and looking forward to hearing from you.

Regards Jay
  Reply With Quote

Old   December 13, 2002, 01:58
Default Re: Outlet velocity boundary condition
  #2
Atul T. Shinde
Guest
 
Posts: n/a
Dear Jay, At inelt, give whatever avaialable. At one outlet,use Outflow condition and at the other outlet can go for pressure condition. Based on this solution, u will have the idea of volume fraction at each outlet. Try out.
  Reply With Quote

Old   December 13, 2002, 06:32
Default Re: Outlet velocity boundary condition
  #3
Jay
Guest
 
Posts: n/a
Thanks Atul.

Yes, I can find the volume fraction the way you suggested. However, in my case I have to maintain a ratio between to outlet (recycle ratio).

Thanks Jay

  Reply With Quote

Old   December 13, 2002, 18:07
Default Re: Outlet velocity boundary condition
  #4
Amid Naz
Guest
 
Posts: n/a
Using velocity outlet means the flow is incompressible. Therefore, the the volume fraction at the outlet can be determined by the area ratio directly..Using outflow BC is Ideal for the case.GOOD LUCK.
  Reply With Quote

Old   December 15, 2002, 08:27
Default Re: Outlet velocity boundary condition
  #5
rk
Guest
 
Posts: n/a
You should never use the combination of velocity inlet, pressure outlet & outflow if you have one inlet & 2 outlets. You can use velocity inlet & 2 pressure outlets or velocity inlet & 2 outflow conditions.

Since you don't know the fraction of mass flow going out, you should know atleast the pressures at the outlets. This will automatically calculates the percentage massflow out!

Thanks,

rk
  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
Outlet boundary condition for wave flume with interFoam solver Arnoldinho OpenFOAM 9 July 10, 2018 05:15
How to set the Heat Flux boundary condition at Outlet creddy_trddc CFX 3 September 21, 2011 07:44
RPM in Wind Turbine Pankaj CFX 9 November 23, 2009 04:05
Implications for heat transfer when outlet pressure boundary condition used Blob CFX 2 March 26, 2009 06:22
Outlet boundary condition CN FLUENT 6 May 22, 2005 09:37


All times are GMT -4. The time now is 04:19.