[lrl3512]

Hi,

I am currently using the icoreactingMultiphaseInterFoam solver for my research. However, while examining the source code, I noticed that the species equation is using instead of .I'm curious why，According to conservation of mass，
Would anyone be able to provide some information or resources to help me understand this issue? I would greatly appreciate any suggestions or guidance that can help me resolve this question.

Thank you.

forAll(X_, i)
    {
        if (inertIndex_ != i)
        {
            volScalarField& Yi = X_[i];

            phiYiCorrs.set
            (
                i,
                new surfaceScalarField
                (
                    "phi" + Yi.name() + "Corr",
                    fvc::flux
                    (
                        phi,
                        Yi,
                        "div(phi," + Yi.name() + ')'
                    )
                )
            );

            surfaceScalarField& phiYiCorr = phiYiCorrs[i];

            forAllConstIter
            (
                multiphaseInterSystem::phaseModelTable,
                this->fluid().phases(),
                iter2
            )
            {
                //const volScalarField& alpha2 = iter2()().oldTime();
                const volScalarField& alpha2 = iter2()();

                if (&alpha2 == &alpha1)
                {
                    continue;
                }

                phiYiCorr += fvc::flux
                (
                   -fvc::flux(-phir, alpha2, phirScheme),
                    Yi,
                    phirScheme
                );
            }