small confusion on the div() term.

nikesh · March 7, 2013, 06:29

Hii Foamers,
I am modifying one of the turbulence models. In that process I have to introduce a new term in the source code, D/Dt(k_/omega_) which can be written as d/dt(k_/omega_)+ fvc::div(phi_,k_/omega_) for incompressible flows. Also considering steady state, we have:

D/Dt(k_/omega_) = fvc::div(phi_,k_/omega_)

Now my doubt is::in openfoam, the RHS of equation is solved based on FVM so, when these terms are discretized, is the cell-volume already included in it or do we need to specify it in the source code itself?

nikesh · March 7, 2013, 07:19

Or to put it in another words......
what I want is "D/Dt(k/omega)" and not "integral of D/Dt(k/omega) dV".
i.e. when I assign this new Field,
volScalarField DDtkw = fvc::div(phi_,k_/omega_)
what I get is DDtkw = integral of div(phi, k/omega) dV
Did I get it right here?

nikesh · March 7, 2013, 23:11

Nobody with insights in this, really??
I had even posted this problem in another location, yet no response in there too....

How to deal with the divergence terms.....??

Maybe the question is rather clearer in the above mentioned forum.
Anyone???? help!!

March 7, 2013, 06:29	small confusion on the div() term.	#1
nikesh New Member Nick Join Date: Nov 2011 Location: Daejeon, South Korea Posts: 26 Rep Power: 2	Hii Foamers, I am modifying one of the turbulence models. In that process I have to introduce a new term in the source code, D/Dt(k_/omega_) which can be written as d/dt(k_/omega_)+ fvc::div(phi_,k_/omega_) for incompressible flows. Also considering steady state, we have: D/Dt(k_/omega_) = fvc::div(phi_,k_/omega_) Now my doubt is::in openfoam, the RHS of equation is solved based on FVM so, when these terms are discretized, is the cell-volume already included in it or do we need to specify it in the source code itself?

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March 7, 2013, 07:19		#2
nikesh New Member Nick Join Date: Nov 2011 Location: Daejeon, South Korea Posts: 26 Rep Power: 2	Or to put it in another words...... what I want is "D/Dt(k/omega)" and not "integral of D/Dt(k/omega) dV". i.e. when I assign this new Field, volScalarField DDtkw = fvc::div(phi_,k_/omega_) what I get is DDtkw = integral of div(phi, k/omega) dV Did I get it right here?

March 7, 2013, 23:11		#3
nikesh New Member Nick Join Date: Nov 2011 Location: Daejeon, South Korea Posts: 26 Rep Power: 2	Nobody with insights in this, really?? I had even posted this problem in another location, yet no response in there too.... How to deal with the divergence terms.....?? Maybe the question is rather clearer in the above mentioned forum. Anyone???? help!!