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

The convergence problem of IcoFoam with cyclic boundary

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   September 9, 2020, 18:55
Default The convergence problem of IcoFoam with cyclic boundary
  #1
New Member
 
Duc Anh
Join Date: Dec 2018
Posts: 22
Rep Power: 7
anhkenyt is on a distinguished road
Hi all,
I run cavity case with cyclic boundary which applies in two sides (the top still moves with constants velocity ) with icoFoam.Of course, I want a solution of U, p as good as impossible.
When I check the residual of the solver, I realize residual of p very higher than the case without cyclic boundary(~1)
What I don't understand is:

1. When checking the convergence of solver, we just care initialResidual ? that correct?

2. If my opinion is correct, how to decrease the residual of p in my case (To get a correct solution)?. If not, can you give me some suggestions to solve my problem?

This is fvSolution file of mine
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  3.0.1                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    location    "system";
    object      fvSolution;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

solvers
{
    p
    {
        solver          PCG;
        preconditioner  DIC;
        tolerance       1e-06;
        relTol          0.05;
    }

    pFinal
    {
        $p;
        relTol          0;
    }

    U
    {
        solver          smoothSolver;
        smoother        symGaussSeidel;
        tolerance       1e-05;
        relTol          0;
    }
}


PISO
{
    nCorrectors     2;
    nNonOrthogonalCorrectors 0;
    pRefCell        0;
    pRefValue       0;
}
PIMPLE
{
    nOuterCorrectors 1;
    nCorrectors     2;
    nNonOrthogonalCorrectors 2;
    pRefCell        0;
    pRefValue       0;
}
And 0/U and 0/p
Code:
/*--------------------------------*- C++ -*----------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Version:  6
     \\/     M anipulation  |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volVectorField;
    object      U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 1 -1 0 0 0 0];

internalField   uniform (0 0 0);

boundaryField
{
    movingWall
    {
        type            fixedValue;
        value           uniform (1 0 0);
    }
	inlet
    {
        type            cyclic;
       // value           uniform (0.001 0 0);
    }
    outlet
    {
		//type zeroGradient;
		type cyclic   ;
    };
    fixedWalls
    {
        type            noSlip;
    }

    frontAndBack
    {
        type            empty;
    }
}

// ************************************************************************* //
Code:
/*--------------------------------*- C++ -*----------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Version:  6
     \\/     M anipulation  |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volScalarField;
    object      p;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 2 -2 0 0 0 0];

internalField   uniform 0;

boundaryField
{
    movingWall
    {
        type            zeroGradient;
    }
	inlet
    {
        type            cyclic;
       // value           uniform (0.001 0 0);
    }
    outlet
    {
		//type zeroGradient;
		type cyclic   ;
    }
    fixedWalls
    {
        type            zeroGradient;
    }

    frontAndBack
    {
        type            empty;
    }
}

// ************************************************************************* //
Please find in the attachment the residual results for the simulation.
I will be happy to get your feedback.

Regard!
Attached Images
File Type: png Screenshot from 2020-09-10 05-43-39.png (6.7 KB, 13 views)
anhkenyt is offline   Reply With Quote

Reply

Tags
convergence of icofoam, cyclic boundaries, residual control


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
sliding mesh problem in CFX Saima CFX 46 September 11, 2021 07:38
Radiation in semi-transparent media with surface-to-surface model? mpeppels CFX 11 August 22, 2019 07:30
Waterwheel shaped turbine inside a pipe simulation problem mshahed91 CFX 3 January 10, 2015 11:19
Possible createPatch/createBaffles bug? simpomann OpenFOAM Bugs 2 July 15, 2014 07:07
RPM in Wind Turbine Pankaj CFX 9 November 23, 2009 04:05


All times are GMT -4. The time now is 05:14.