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Negative values for minimum alphas

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Old   June 28, 2016, 04:04
Unhappy Negative values for minimum alphas
Taher Chegini
Join Date: Nov 2014
Location: Houston, Texas
Posts: 85
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Hi all,

I am using compressibleInterFoam solver to model an internal flow, mixture of water and air. The problem is that I keep getting negative values for minimum alpha of air and of water. I tried implementing limiters such as valLeer01 and MUSCL01 methods for div(phi,alpha) and div(phirb,alpha) but no success. I looked through the forum and found a similar post but it couldn't solve my problem. Here are the numerical schemes that I am using:
    default         Euler;

    default cellLimited Gauss linear 0.5;
    grad(U) cellLimited Gauss linear 0.5; 

    div(phi,alpha)  Gauss MUSCL01;
    div(phirb,alpha) Gauss MUSCL01;

    div(rhoPhi,U)  Gauss vanLeerV;
    div(phi,p)      Gauss upwind;

    div(((rho*nuEff)*dev2(T(grad(U))))) Gauss linear;
    "div\(phi,(k|thermo:rho.water|thermo:rho.air|)\)"	Gauss linearUpwind default;
    "div\(rhoPhi,(T|K|epsilon|k)\)"     Gauss linearUpwind default;

    default Gauss linear limited 1.0;

    default         linear;

    default	limited 1.0; 
and here are the solver options that I am using for alphas:
        nAlphaCorr      1;
        nAlphaSubCycles 2;
        cAlpha          1;
        icAlpha         0.25;
        MULESCorr       yes;
        nLimiterIter    8;
        alphaApplyPrevCorr  true;

        solver          smoothSolver;
        smoother        symGaussSeidel;
        tolerance       1e-6;
        relTol          1e-3;
Any suggestion is appreciated.
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