[mateusdias89]

Hello,

I am looking into the unburnt absolute enthalpy equation file of OpenFOAM (EauEqn.H) from the solver XiFoam and I have a question about its implementation.
I still can not understand why the terms of the transport equation were no enthalpy is present are multiplied by rho/thermo.rhou() and would appreciate if someone could explain me this and maybe we can discuss it in detail.

fvScalarMatrix heauEqn
    (
        fvm::ddt(rho, heau) + mvConvection->fvmDiv(phi, heau)
      + (fvc::ddt(rho, K) + fvc::div(phi, K))*rho/thermo.rhou()
      + (
            heau.name() == "eau"
          ? fvc::div
            (
                fvc::absolute(phi/fvc::interpolate(rho), U),
                p,
                "div(phiv,p)"
            )*rho/thermo.rhou()
          : -dpdt*rho/thermo.rhou()
        )
      - fvm::laplacian(turbulence->alphaEff(), heau)

        // These terms cannot be used in partially-premixed combustion due to
        // the resultant inconsistency between ft and heau transport.
        // A possible solution would be to solve for ftu as well as ft.
        //- fvm::div(muEff*fvc::grad(b)/(b + 0.001), heau)
        //+ fvm::Sp(fvc::div(muEff*fvc::grad(b)/(b + 0.001)), heau)

     ==
        fvOptions(rho, heau)
    );

Thanks in advance,
Mateus Dias Ribeiro

[sempionato]

Hi Mateus, do you advanced on this question?

Here, in Sao Jose dos Campos, we research the XiFoam implementation in partially pre-mixed combustion but these terms are puzzling us.

The temperatures are presenting some discrepancies in partially premixed cases and I think that is due this terms.

Thanks,

Guilherme.