[Eclipseyin]

Hello, I am running a SFD-solver which is based on icoFoam. The SFD-solver (SFD: Selective Frequency Damping ) computes a steady laminar flow over a plate where a cylinder roughness is set on.



The grid is very fine so I computed with very small time step (1.5e-5 s) so that the CFL-number would be never above 0.9 . For the system/fvSolution file I set up the pressure (for solving the pressure Poisson equation) as
p
{
solver PCG;
preconditioner DIC;
tolerance 5e-09;
relTol 0.005;
}


at the beginning, then I thought the tolerance could be chosen with a higher one, so I changed it to 1e-8. After some while, the CFL-number began to drop and then somehow increased over 1.0, the case exploded .


Could someone tell me why the CFL-number first dropped and then increased? Can I save my case by changing the tolerance to 5e-9 again?

[Eclipseyin]

The equation system is changed in the icoFoam to



fvVectorMatrix UEqn
(
fvm::ddt(U)
+ fvm::div(phi, U)
- fvm::laplacian(nu, U)
+ fvm::Sp(chi, U) // added
- fvc::Sp(chi, Ubar) // added
);
which is the SFD method . It can compute a steady base flow field U for the perturbation computation in the transition analysis.

[pratyush_6174]

I want to implement Selective Frequency Damping (SFD) to icoFoam solver to get the steady state solution can you please help regarding this how can i achive this.

Thanks !!

[Ghazal]

Originally Posted by pratyush_6174

I want to implement Selective Frequency Damping (SFD) to icoFoam solver to get the steady state solution can you please help regarding this how can i achive this.

Thanks !!

I also need to use it for combustion to get steady flames. Can you tell me how you managed to do so?