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

Pressure iterations reach max

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   September 5, 2021, 07:31
Post Pressure iterations reach max
  #1
Member
 
saidc
Join Date: Feb 2020
Location: Türkiye
Posts: 60
Rep Power: 6
saidc. is on a distinguished road
Hi,

I'm solving a natural convection case with the buoyantPimpleFoam. The pressure solver reaches maximum iteration nearly all outer loops even if the checkMesh results looks fine and also the convergence criteria not tight.
  • GAMG: Solving for p_rgh, Initial residual = 0.0475859098409, Final residual = 0.0157404857286, No Iterations 300
I've tried to get better mesh, more robust schemes (upwind), reduce relaxation factors and tolerances but none of them worked. Maybe I have missed something about boundary condition but they look fine either to me. Why do not converge? I am open to any suggestions. Files are attached.

Kind regards,
Said.

For quick look;


Code:
cells:            984891
Checking geometry...
     Overall domain bounding box (-0.00334 -0.00334 -1.90819582357e-17) (0.00334 0.00334 0.08684)
    Mesh has 3 geometric (non-empty/wedge) directions (1 1 1)
    Mesh has 3 solution (non-empty) directions (1 1 1)
    Boundary openness (2.79406534204e-16 6.89998282164e-16 1.24139673575e-16) OK.
    Max cell openness = 2.51976925248e-16 OK.
    Max aspect ratio = 6.09829454585 OK.
    Minimum face area = 6.12453563709e-09. Maximum face area = 1.55316884489e-07.  Face area magnitudes OK.
    Min volume = 2.2134204e-13. Max volume = 1.88150115538e-11.  Total volume = 2.30561433658e-06.  Cell volumes OK.
    Mesh non-orthogonality Max: 64.9766553786 average: 15.615597926
    Non-orthogonality check OK.
    Face pyramids OK.
    Max skewness = 0.837135365112 OK.
     Coupled point location match (average 0) OK.
Code:
    p_rgh
     {
    solver           GAMG;
    tolerance        1e-4;
    relTol           0.05;
    smoother         GaussSeidel;
    nPreSweeps     0;
    nPostSweeps     2;
    nFinestSweeps    2;
    scaleCorrection  yes;
    directSolveCoarsestLevel false;
    cacheAgglomeration    on;
    nCellsInCoarsestLevel 1000;
    agglomerator     faceAreaPair;
    minIter           4;
    maxIter           300;
    mergeLevels      1;
    }

    p_rghFinal
    {
    solver           GAMG;
    tolerance        1e-6;
    relTol           0.05;
    smoother         GaussSeidel;
    nPreSweeps     0;
    nPostSweeps     2;
    nFinestSweeps    2;
    scaleCorrection  yes;
    directSolveCoarsestLevel false;
    cacheAgglomeration    on;
    nCellsInCoarsestLevel 1000;
    agglomerator     faceAreaPair;
    minIter           4;
    maxIter           300;
    mergeLevels      1;
     }
Code:
ddtSchemes
{
    default         Euler;
}
gradSchemes
{
    //default     cellMDLimited Gauss linear 0.5;
    //grad(U)    cellMDLimited Gauss linear 0.5;
    default     cellLimited Gauss linear 0.5;
    grad(U)    cellLimited Gauss linear 0.5;
}
divSchemes
{
    default         none;
    //div(phi,U)      Gauss linearUpwind grad(U);
    //div(phi,K)      Gauss linearUpwind default;
    //div(phi,h)      Gauss linearUpwind default;
    div(phi,U)      Gauss upwind grad(U);
    div(phi,K)      Gauss upwind default;
    div(phi,h)      Gauss upwind default;
    div(((rho*nuEff)*dev2(T(grad(U))))) Gauss linear;
}
laplacianSchemes
{
    default         Gauss linear limited 0.777;
}
interpolationSchemes
{
    default         linear;
}
snGradSchemes
{
    default         limited 0.777;
}
Attached Files
File Type: zip nat_Conv_BCC.zip (24.8 KB, 1 views)

Last edited by saidc.; September 12, 2021 at 10:36.
saidc. is offline   Reply With Quote

Reply

Tags
iteration, natural convection, pressure

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
Converging Diverging Nozzle with dbnsTurbFoam Saleh Abuhanieh OpenFOAM Running, Solving & CFD 4 December 13, 2019 11:26
Suppress twoPhaseEulerFoam energy AlmostSurelyRob OpenFOAM Running, Solving & CFD 33 September 25, 2018 18:45
chtMultiRegionSimpleFoam turbulent case Aditya Patil OpenFOAM Running, Solving & CFD 6 April 24, 2017 23:13
Cannot run the code properly: very large time step continuity error crst15 OpenFOAM Running, Solving & CFD 9 December 14, 2014 19:17
SLTS+rhoPisoFoam: what is rDeltaT??? nileshjrane OpenFOAM Running, Solving & CFD 4 February 25, 2013 05:13


All times are GMT -4. The time now is 08:59.