[mostanad]

Hi everybody,
I am using the pimpleFoam solver for a yield stress Herschel-Bulkley flow. The question is about my setting in fvSolution script.

PIMPLE
{
    momentumPredictor   on;
    nOuterCorrectors    15;
    nCorrectors         3;
    nNonOrthogonalCorrectors 0;
    pRefCell            0;
    pRefValue           0;
    turbOnFinalIterOnly no;
}

And specifically, its turbOnFinalIterOnly setting. Is it needed for me to update the viscosity in every outer Corrector iteration for a non-Newtonian fluid? Or just updating at the end of solution and the current time step is enough.
Cheers,
Mohammad

[frantov]

If your problem is significantly turbulent, you might want to solve k and omega at each time-step, by setting this flag turbOnFinalIterOnly

If not, then save calculations and cpu tine

[mostanad]

Hi Francisco
Thanks for your reply. What about a non-Newtonian flow which needs viscosity update?
Mohammad

[frantov]

Originally Posted by mostanad

Hi Francisco
Thanks for your reply. What about a non-Newtonian flow which needs viscosity update?
Mohammad

Hi Mohammad

As far as I understand, OpenFOAM includes a library of strain-rate dependent viscosity models, where they construct the viscosity as a field (scalar).

This construction is function of some constants but also the strainRate() which is dependent on the flow conditions. You can visualize nu (viscosity) in paraview, and check that it is actually updated every iteration.