# What is advection term of incompressible turbulence model

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

 December 5, 2008, 01:29 Hi everyone: i have find in #1 Senior Member   wayne.zhang Join Date: Mar 2009 Location: Shanghai, Shanghai, P.R.China Posts: 308 Rep Power: 11 Hi everyone: i have find in kEpsilon and KomegaSST,both k , epsilone,Omega equation has the advection term like this: + fvm::div(phi_, k_) - fvm::Sp(fvc::div(phi_), k_) but i think the div(phi_)should be "0" for incompressible flow. and why not write as : - fvm::Sp(fvc::div(k_), phi_) or - fvm::Sp(fvm::div(k_), phi_) thanks yours wayne

 December 5, 2008, 03:47 Hi Wayne, there has already be #2 Member   Ville Tossavainen Join Date: Mar 2009 Posts: 60 Rep Power: 10 Hi Wayne, there has already been discussion about this matter. Try to search for it, because I cannot remember the details. You shouldn't worry too much about it, since the divergence term goes to zero as the solution converges.

 December 6, 2008, 08:46 hi Ville thanks，i will se #3 Senior Member   wayne.zhang Join Date: Mar 2009 Location: Shanghai, Shanghai, P.R.China Posts: 308 Rep Power: 11 hi Ville thanks，i will search it now.if you find please tell me .there are some similar term in the diffusion term too : tmp kEpsilon::divDevReff(volVectorField& U) const { return ( - fvm::laplacian(nuEff(), U) - fvc::div(nuEff()*dev(fvc::grad(U)().T())) ); } the red part will be 1/3*nuEff*grad(div(U)),and for incompressible flow it will be zero too. the problem is that these terms should be zero in theory,but not in numerical,so i don`t know why add these terms here with the danger of introduce the numerical error. i think maybe there is something i do not know.so any one could help me ? thanks yours wayne

 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 N.R. CFX 8 December 8, 2014 15:22 Ameya Durve FLUENT 0 February 24, 2009 14:52 Anil CFX 4 October 3, 2007 09:09 astro1 Main CFD Forum 5 May 5, 2007 11:07 Juan CFX 4 June 29, 2005 03:54

All times are GMT -4. The time now is 01:22.