pressure corrector turbFoam

 User Name Remember Me Password
 Register Blogs Members List Search Today's Posts Mark Forums Read

 LinkBack Thread Tools Display Modes
 July 8, 2009, 13:25 pressure corrector turbFoam #1 New Member   Join Date: Jun 2009 Location: Belgium Posts: 3 Rep Power: 10 Sponsored Links Dear all, I have a question concerning the pressure correction in turbFoam: Code: fvScalarMatrix pEqn ( fvm::laplacian(rUA, p) == fvc::div(phi) ); The right hand side is implemented using phi instead of U to avoid an extra interpolation of U to Uf (see http://www.tfd.chalmers.se/~hani/kur...7/rhiechow.pdf). This confuses me a little bit as I expected the right hand side to be fvc::div(H/A)=sumOverFaces(Hf/Af.Sf) and with phi=Uf.Sf and Uf=H/A at this point in the algorithm, I assume the code does the following: fvc::div(phi)=fvc::div(Hf/Af.Sf)=sumOverFaces(Hf/Af.Sf.Sf) with one Sf too many I probably overlook something, can someone tell me what? Thanks in advance, Sara Last edited by Sara D; July 9, 2009 at 03:26.
 Sponsored Links

July 12, 2009, 13:38
#2
Senior Member

Henrik Rusche
Join Date: Mar 2009
Location: Braunschweig, Niedersachsen, Germany
Posts: 277
Rep Power: 11
Sara,

I think what you are missing is that fvc::div(phi) DOES a simple sum over all cell faces and DOES NEITHER dot-product with the face area vectors NOR interpolate to the face.

Yes, this is not intuitive, but it makes a lot of sense when you think about it.

Unfortunately, on page P-39 the Programmer's Guide says:
Quote:
 The fvc::div function can take as its argument either a surfaceField, in which case is specified directly, or a volField which is interpolated to the face by central differencing as described in Section 2.4.10:
where - I think - it should read:
Quote:
 The fvc::div function can take as its argument either a surfaceField, in which case is specified directly, or a volField which is interpolated to the face by central differencing as described in Section 2.4.10:
Henrik

 July 13, 2009, 03:34 thanks #3 New Member   Join Date: Jun 2009 Location: Belgium Posts: 3 Rep Power: 10 Henrik, Thank you, now I understand. That is indeed a pitfall and the programmers guide doesn't help in this case. Thanks a lot for clarifying, Sara

 Thread Tools Display Modes Linear Mode

 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 OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post Antech Main CFD Forum 0 April 25, 2006 02:15 Dan Moskal Main CFD Forum 0 October 24, 2002 22:02 chong chee nan FLUENT 0 December 29, 2001 06:13 HB &DS CFX 0 January 9, 2000 14:19 DS & HB Main CFD Forum 0 January 8, 2000 16:00

 Sponsored Links

All times are GMT -4. The time now is 12:07.

 Contact Us - CFD Online - Top