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-   -   temperature equation for one phase in multiphase solver (http://www.cfd-online.com/Forums/openfoam-programming-development/74961-temperature-equation-one-phase-multiphase-solver.html)

 romant April 13, 2010 05:06

temperature equation for one phase in multiphase solver

Hej,

I have been working with the interPhaseChangeFoam solver for a while now, and have started writing a phase change model based on temperature. Right now the temperature is still given via the dictionary input.

I wanted to add the energy equation for the fluid phase to this solver. The governing equation is
http://img541.imageshack.us/img541/3011/energyeq.png

which I tried implementing like this

Code:

{

//    const volScalarField rhoAlpha = cp * rho1 * alpha1; // for time derivative
volScalarField rhoAlpha
(
"rhoAlpha",
cp * rho1 * alpha1
);

surfaceScalarField phiAlpha
(
"phiAlpha",
phi * rho1 * cp  * fvc::interpolate(alpha1) //check with rhoPhi from the alphaEqn.H file
//        rhoPhi * cp //* fvc::interpolate(alpha1)
);

volScalarField lambdaFAlpha
(
"lambdaFAlpha",
lambdaF * alpha1
);

Pair<tmp<volScalarField> > mDotAlphal = twoPhaseProperties->mDotAlphal();
const volScalarField mDotAlphac = mDotAlphal[0]();

fvScalarMatrix TEqn
(
fvm::ddt(rhoAlpha,T)
+ fvm::div(phiAlpha, T)
- fvm::laplacian(lambdaFAlpha, T)
== mDotAlphac * ifg

);

TEqn.relax();
TEqn.solve();

Info << "Max(T): " << max(T).value() << " K "
<< "Min(T): " << min(T).value() << " K" << endl;

}

Unfortunately, I have had no success in actually using this within the solver, the results are completely bogus. One thing that is obvious is that there might be a problem with the alpha1 attachment to the equation.

My first thought was to maybe be able to extract the mesh that contains water alpha1>0, and impose boundary conditions onto the interface cells. Is there a way to do it, or does somebody else see what could be wrong with the implementation of this equation?

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