CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Running, Solving & CFD

Advective BC for velocity

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   January 17, 2016, 20:18
Default Advective BC for velocity
  #1
D.B
Member
 
DB
Join Date: Apr 2011
Posts: 87
Rep Power: 15
D.B is on a distinguished road
Hi All,
I am using icofoam for my laminar-incompressible flow simulation. I want a non-reflective BC for my exit boundary in openFoam. I have gone through various posts on the web-site and I get a feel that most of these posts are really old and there have been changes in the software since then henc I am making this new thread.

I want an advective boundary condition for my velocity which solves the Euler equation

dU/dt + U*dU/dx = 0 at the exit boundary. I thought advective BC would be useful and gave my BC as

outlet
{
type advective;
phi U;
}

but it gives and error that it tried to look for a scalar and U is a volvectorfield as shown below

"--> FOAM FATAL ERROR:

lookup of U from objectRegistry region0 successful
but it is not a surfaceScalarField, it is a volVectorField

"

So it seems(correct me if I am wrong) that the advective BC is only for scalar transport variables and not for vector fields like U. Is there a BC which can help me do that, since I see that the user guides haven't been updated to include new BC's.

If not then I might have to code my new BC, but I would prefer to not write a new code when an efficient one already exists. Any suggestions would be helpful.

Cheers,
__________________
-D.B
D.B is offline   Reply With Quote

Old   January 18, 2016, 02:09
Default
  #2
Senior Member
 
akidess's Avatar
 
Anton Kidess
Join Date: May 2009
Location: Germany
Posts: 1,377
Rep Power: 29
akidess will become famous soon enough
phi is a flux, not a velocity. Set phi to phi and all will be good.
__________________
*On twitter @akidTwit
*Spend as much time formulating your questions as you expect people to spend on their answer.
akidess is offline   Reply With Quote

Reply

Tags
non-re, openfoam

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
advective BC Pascal_doran OpenFOAM Running, Solving & CFD 2 May 30, 2019 23:31
whats the usage of advective and convective BC,differences and formulas? immortality OpenFOAM 1 July 15, 2013 05:11
Initial values for advective BC Pascal_doran OpenFOAM Pre-Processing 0 July 29, 2010 16:29
Advective BC: local velocity? dany OpenFOAM Running, Solving & CFD 0 July 3, 2009 08:48
MONOTONIC ADVECTIVE SCHEME Ferreira Main CFD Forum 0 June 4, 2008 14:14


All times are GMT -4. The time now is 14:33.