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

Phase field: calculation of the |grad f| div(grad f/|grad f|) term

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

Reply
 
LinkBack Thread Tools Display Modes
Old   November 2, 2011, 10:44
Default Phase field: calculation of the |grad f| div(grad f/|grad f|) term
  #1
Member
 
valerio
Join Date: Jun 2009
Location: Nancy
Posts: 30
Rep Power: 8
Alucard is on a distinguished road
The equation i've to solve (Y.Sun,C. Beckermann, Sharp interface tracking using phase-field equation, Journal of computational physics) is:

df/dt+V*grad f=a*[ laplacian f+f*(1-f)/b-|grad f| div [ grad f/|grad f|]]
with a,b parameters (or constants).

how can I calculate the "|grad f| div(grad f/|grad f|) " term in an esplicit way in OF?

This is how I discretised the equation (except the term i'm talking about) neglecting, for the moment, the transport term:

fvScalarMatrix phaseEqn
(
fvm::Sp(1./runTime.deltaT(),phase)
-ophase/runTime.deltaT()
-a*fvm::laplacian(phase)
-1./b*ophase*(1.-ophase*ophase)
+?????
);
phaseEqn.relax();
iterations=solve(phaseEqn).nIterations();

f=phase and ophase is the old time step value of the field (i know i can use ddt directly but i need to perform some coupling later so i prefer to be "free" to discretise by myself the temporal derivative)

Thank you!

Last edited by Alucard; November 2, 2011 at 12:16.
Alucard is offline   Reply With Quote

Reply

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
problem in Phase Field method qunwuhe@hotmail.com Main CFD Forum 6 February 16, 2011 13:20
how 2 freeze 1 phase flow field & start lagrangian KK CFX 5 February 14, 2008 17:48
Electric Field calculation JamesT Phoenics 5 May 31, 2007 04:44
phase field or Cahn-Hilliard method dusky.he Main CFD Forum 3 February 2, 2006 17:43
Differences between VOF and phase field 2L Main CFD Forum 2 July 4, 2004 13:30


All times are GMT -4. The time now is 14:35.