[renyun0511]

Hi all,

Recently, I have been studying the unsteady simulation of pumps by using OpenFOAM. Then, I try to simulate the Timisoara swirl generator case with transientSimpleDyMFoam solver firstly. The solver and case are both downloaded from the webpage: http://openfoamwiki.net/index.php/Sig_Turbomachinery_/_Timisoara_Swirl_Generator

But, the case was diverged after several steps, and the log file is in the attached files. I don't know why it was diverged though I haven't changed anything? Would someone like to help me? I will appreciate it!

Attachment 20360

here is the setup of fvSolution and controdict:

fvSolution file:

solvers
{
p PCG
{
preconditioner DIC;
tolerance 1e-05;
relTol 0.002;
minIter 2;
maxIter 140;
};
pFinal PCG
{
preconditioner DIC;
tolerance 1e-05;
relTol 0.001;
minIter 2;
maxIter 280;
};
pcorr PCG
{
preconditioner DIC;
tolerance 1e-05;
relTol 0.001;
minIter 2;
maxIter 180;
};

U PBiCG
{
preconditioner
{ type DILU;}
smoother
{ type DILU; }

minIter 1;
maxIter 4;
tolerance 1e-07;
relTol 0;
};

k PBiCG
{
preconditioner
{ type DILU; }
smoother
{ type DILU; }

minIter 1;
maxIter 3;
tolerance 1e-07;
relTol 0;
};
epsilon PBiCG
{
preconditioner
{ type DILU; }
smoother
{ type DILU; }

minIter 1;
maxIter 3;
tolerance 1e-07;
relTol 0;
};
omega PBiCG
{
preconditioner
{ type DILU; }
smoother
{ type DILU; }

minIter 1;
maxIter 3;
tolerance 1e-07;
relTol 0;
};
}
PISO
{
nCorrectors 0;
nOuterCorrectors 10;
nNonOrthogonalCorrectors 0;
correctPhi false;
}

relaxationFactors
{
p 0.3;
U 0.75;
k 0.5;
epsilon 0.5;
omega 0.5;
}

Controdict file:

Attachment 20361

Best Regards,

Yun Ren

[deepsterblue]

You may want to switch off the relative tolerances in the pressure solver.

[renyun0511]

Hi Sandeep,

What do you mean about switch off the relative tolerances in the pressure solver. Sorry, I can't understand. Could I have some more details, please. And I just sent an email to you. Hoping for your reply. Thank you very much!

Regard,

Yun Ren

[deepsterblue]

Sorry for being cryptic. Set relTol to 0.0 for pressure in fvSolution.