CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Running, Solving & CFD

Negative values for minimum alphas

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   June 28, 2016, 05:04
Unhappy Negative values for minimum alphas
  #1
Senior Member
 
Taher Chegini
Join Date: Nov 2014
Location: Houston, Texas
Posts: 125
Rep Power: 12
Taataa is on a distinguished road
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:
Code:
ddtSchemes
{
    default         Euler;
}

gradSchemes
{
    default cellLimited Gauss linear 0.5;
    grad(U) cellLimited Gauss linear 0.5; 
}

divSchemes
{
    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;
}

laplacianSchemes
{
    default Gauss linear limited 1.0;
}

interpolationSchemes
{
    default         linear;
}

snGradSchemes
{
    default	limited 1.0; 
}
and here are the solver options that I am using for alphas:
Code:
    "alpha.*"
    {
        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.
Taataa is offline   Reply With Quote

Reply

Tags
compressibleinterfoam

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Preventing negative scalar (UDS) values?? Matthew Brannock FLUENT 5 September 1, 2020 13:32
Mass flow rate boundary condition with negative values ashtonJ CFX 3 November 26, 2014 06:21
strange node values @ solid/fluid interface - help JB FLUENT 2 November 1, 2008 13:04
[blockMesh] Axisymmetrical mesh Rasmus Gjesing (Gjesing) OpenFOAM Meshing & Mesh Conversion 10 April 2, 2007 15:00
Negative Stream Function Values - How do I get the Chris Marriner FLUENT 1 March 13, 2002 21:10


All times are GMT -4. The time now is 10:59.