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

How to get convergence with simpleFoam?

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   May 18, 2022, 04:48
Smile How to get convergence with simpleFoam?
  #1
New Member
 
Denny Mathew Alex
Join Date: Mar 2022
Location: Essen, Germany
Posts: 2
Rep Power: 0
dennymathewalex is on a distinguished road
Hello Everyone 😊,
I am Denny and I am new to OpenFoam. I am learning OpenFoam by simulating a flow inside a rectangular chamber with simpleFoam solver. The boundaries are shown in the figures (inlet-Green, outlet-Red, wall-Blue). The geometry was created using Salome and mesh was generated using snappyHexMesh (only castellated Mesh part is True). Using the checkMesh, the quality of the mesh is OK. I ran the simulation to 2000 and 6000 time steps with delta t of 1 but could not achieve convergence. I have attached the velocity plot for time steps 1802 and 1902.
I have pasted the boundary condition U and p, controlDict, fvSchemes, fvSolution below.
What are the steps to be taken to get a good convergence in this case?
Thank you for your help 😊.
-------------------- U --------------------------------
internalField uniform (0 0 0);

boundaryField
{
inlet
{
type fixedValue;
value uniform (1 0 0);
}

outlet
{
type zeroGradient;
value uniform (0 0 0);
}

wall
{
type noSlip;
value uniform (0 0 0);
}

}


---------------- p ----------------------------
internalField uniform 0;

boundaryField
{
inlet
{
type zeroGradient;
}

outlet
{
type fixedValue;
value uniform 0;
}

wall
{
type zeroGradient;
}

}

--------------------- controlDict ------------------------

application simpleFoam;

startFrom startTime;

startTime 1;

stopAt endTime;

endTime 6000;

deltaT 1;

writeControl timeStep;

writeInterval 100;

purgeWrite 0;

writeFormat ascii;

writePrecision 6;

writeCompression off;

timeFormat general;

timePrecision 6;

runTimeModifiable true;

--------------- fvSchemes ---------------------
ddtSchemes
{
default steadyState;
}

gradSchemes
{
default Gauss linear;
}

divSchemes
{
default none;
div(phi,U) bounded Gauss upwind;
div((nuEff*dev2(T(grad(U))))) Gauss linear;
}

laplacianSchemes
{
default Gauss linear corrected;
}

interpolationSchemes
{
default linear;
}

snGradSchemes
{
default corrected;
}

------------------- fvSolution ---------------------
solvers
{
p
{
solver GAMG;
tolerance 1e-06;
relTol 0.1;
smoother GaussSeidel;
}

U
{
solver smoothSolver;
smoother symGaussSeidel;
tolerance 1e-05;
relTol 0.1;
}
}

SIMPLE
{
nNonOrthogonalCorrectors 0;
nCorrectors 3;
consistent yes;

residualControl
{
p 1e-2;
U 1e-3;
}
}

relaxationFactors
{
fields
{
p 1;
}
equations
{
U 0.9; // 0.9 is more stable but 0.95 more convergent
}
}
Attached Images
File Type: jpg inletScreenshot.jpg (20.1 KB, 9 views)
File Type: jpg outletScreenshot.jpg (19.9 KB, 8 views)
File Type: jpg slice U at 1802 Time Step.jpg (21.4 KB, 8 views)
File Type: jpg slice U at 1902 Time Step.jpg (21.1 KB, 10 views)
dennymathewalex is offline   Reply With Quote

Reply

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
simpleFoam : how to optimize timestep and assess convergence ? Talder OpenFOAM Running, Solving & CFD 2 February 15, 2019 08:48
Simplefoam Convergence Problem after Scaling by 0.001 CFDy OpenFOAM Running, Solving & CFD 4 July 23, 2018 04:27
SimpleFoam: Residual convergence problem miha23 OpenFOAM Running, Solving & CFD 0 April 24, 2018 19:50
Mesh Convergence Study - simpleFoam: Confusing Results Karpfen OpenFOAM 0 February 5, 2018 08:34
no convergence with simplefoam hei@ge OpenFOAM 14 May 22, 2012 09:34


All times are GMT -4. The time now is 15:43.