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Temperature is not calculated in modified CHTMultiregion

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Old   June 27, 2014, 04:28
Default Temperature is not calculated in modified CHTMultiregion
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Gennaro
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Dear all,

I'm working on a modified CHTMultiregion solver in which the energy equation of the fluid part (EEqn.H file) is replaced with:
Code:
{    
    Info<< " ** Calculating CpEff           **\n";        
    CpEff = Cp*pow(T/Tlambda, 5.7);

    Info<< " ** Calculating gT              **\n";        
    gT = pow(rho, 2)*pow(Slambda, 4)*pow(Tlambda, 3)/Alambda; // Instead of Foam::pow

    Info<< " ** Calculating hK              **\n";        
    hK = 4*Sigma*pow(T, 3)*dimensionedScalar("Lref", dimensionSet(0,1,0,0,0), 1);        // Lref is just to have the dimensions of a thermal conductivity
    
    Info<< " ** Calculating fInv            **\n";
    fInv = gT*pow(pow(T/Tlambda, 5.7)*(1 - pow(T/Tlambda, 5.7)), 3);

    Info<< " ** Calculating magSqrGradT     **\n";        
    magSqrGradT = magSqr(fvc::grad(T)) + SMALL;

    Info<< " ** Calculating KEff            **\n";    
    KEff = pow(fInv/magSqrGradT, scalar(1)/scalar(3))/(rho*CpEff);

    Info<< " ** Solving EEqn                **\n";    
    fvScalarMatrix EEqn
    (
        fvm::laplacian(KEff, T)
    );

    Info<< " ** EEqn.relax()                **\n";    
    EEqn.relax();

    Info<< " ** fvOptions.constrain(EEqn)   **\n";    
    fvOptions.constrain(EEqn);

    Info<< " ** EEqn.solve()                **\n";    
    EEqn.solve();

    Info<< " ** fvOptions.correct(T)        **\n";        
    fvOptions.correct(T);

    Info<< " ** thermo.correct()            **\n";
    thermo.correct();

    rad.correct();

    Info<< "Min/max T:" << min(thermo.T()).value() << ' '
        << max(thermo.T()).value() << endl;
}
The solver doesn't crash and the fluid interacts with the solid part.

Unfortunately, the temperature distribution is not calculated! T completely uniform all across the fluid part!

Can anyone help?

I'm happy to send the whole code plus a test case

Thanks

Gennaro
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Old   September 25, 2014, 11:55
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Peng Liang
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hello Gennaro,

have you solved your problem? I am also encountering the same problem as to implement temperature in chtmultiregionfoam. If you please, could you please show me how to add one or more temperature equations into chtmultiregionfoam? Thanks.

Peng
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Old   December 18, 2014, 12:16
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Gennaro
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Hi Peng,

Yes, problem solved! I had to get rid of the code related to the thermophysical properties (they don't apply to helium) in order to have the T field properly written. If you need tips don't hesitate to ask.

Gennaro
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chtmultiregionsimplefoam, energy equation, temperature field

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