openfoam/applications/solvers/heatTransfer/chtMultiRegionFoam/solid/solveSolid.H

{
    fvScalarMatrix hEqn
    (
        fvm::ddt(betav*rho, h)
        - (
            thermo.isotropic()
            ? fvm::laplacian(betav*thermo.alpha(), h, "laplacian(alpha,h)")
            : fvm::laplacian(betav*taniAlpha(), h, "laplacian(alpha,h)")
        )
        ==
        fvOptions(rho, h)
    );

    hEqn.relax();

    fvOptions.constrain(hEqn);

    if (coupled)
    {
        fvMatrixAssemblyPtr->addFvMatrix(hEqn);
    }
    else
    {
        Info<< "\nSolving for solid region "<< solidRegions[i].name() << endl;

        if (finalIter)
        {
            mesh.data::add("finalIteration", true);
        }

        hEqn.solve(mesh.solver(h.select(finalIter)));

        fvOptions.correct(h);

        thermo.correct();

        Info<< "Min/max T:" << min(thermo.T()).value() << ' '
            << max(thermo.T()).value() << endl;

        if (finalIter)
        {
            mesh.data::remove("finalIteration");
        }
    }
}