类似interCondensatingEvaporatingFoam solver 计算结果发散

[hongjiewang]

基于interCondensatingEvaporatingFoam求解器，编写了一个可求解porous区域的求解器。在我设置孔隙率eps为1时（即没有多孔区域，用以和标准的stefanProblem结果做验证），求解的结果和stefanProblem结果相吻合。在我设置孔隙率eps为0.8/0.6/0.5/0.2时，求解结果均发散。
我试图修改了fvSolution中的参数，将relaxationFactors从1逐渐降低到0.1，发散的时间点也从1.6s推迟到了4s，这和relaxationFactors发作用相符合。将p_rgh的solver从PCG改为GAMG，并没有推迟发散时间，反而求解速度更慢
请问我还应该注意哪几个方面用来减小发散的可能性。感谢各位老师~

solvers
{
    alpha.liquid
    {
        nAlphaCorr      2;
        nAlphaSubCycles 2;
        cAlpha          1;

        MULESCorr       no;
        nLimiterIter    5;
    }

    rho
    {
        solver           diagonal;
        tolerance       1e-7;
        relTol          0.1;
    }

    rhoFinal
    {
        $rho;
        tolerance       1e-7;
        relTol          0;
    }

    p_rgh
    {
        solver           GAMG;
        tolerance        1e-9;
        //solver          PCG;
        preconditioner  DIC;
        relTol           0.001;
        smoother         DIC;
    }

    mDotSmearFinal
    {
        solver           PCG;
        tolerance        1e-6;
        preconditioner   DIC;
        relTol           0.00;
        smoother         DIC;
    }

    p_rghFinal
    {
        $p_rgh;
        tolerance        1e-9;
        relTol           0;
        minIter 10;
    }

    pcorrFinal
    {
        $p_rgh;
        tolerance        1e-9;
        relTol           0;
    }


    "(U|h|T.*|k|epsilon|R)"
    {
        solver           smoothSolver;
        smoother        symGaussSeidel;
        tolerance        1e-7;
        relTol           0.;
        minIter          15;
        maxIter          50;
    }

    "(U|h|T.*|k|epsilon|R)Final"
    {
        $U;
        tolerance        1e-7;
        relTol           0;
        maxIter          50;
    }
}

PIMPLE
{
    momentumPredictor   yes;
    nCorrectors         5;
    nNonOrthogonalCorrectors 0;
}

relaxationFactors
{
    equations
    {
        ".*"           0.1;
    }
}

[hongjiewang]

http://blog.sina.com.cn/s/blog_5fdfa7e601010rkx.html 苏老师的博客