CFD Online Discussion Forums - minCollisionDeltaT in PairSpringSliderDashpot.C

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)

- OpenFOAM Running, Solving & CFD (https://www.cfd-online.com/Forums/openfoam-solving/)

- - minCollisionDeltaT in PairSpringSliderDashpot.C (https://www.cfd-online.com/Forums/openfoam-solving/169463-mincollisiondeltat-pairspringsliderdashpot-c.html)

minCollisionDeltaT in PairSpringSliderDashpot.C

dear,
I am now confused with the function of minCollisionDeltaT in PairSpringSliderDashpot.C
I want to find the primary theory, can anyone help me ?
Linmin

Would be very interesting for me too.
The formula does not look like an empircial correlation, but I wonder about the strange exponents

Code:

    // Note:  pi^(7/5)*(5/4)^(2/5) = 5.429675

    scalar minCollisionDeltaT =

        5.429675

       *rMin

       *pow(rhoMax/(Estar_[maxEstarIndex_]*sqrt(UMagMax) + vSmall), 0.4)

       /collisionResolutionSteps_;

The orriginal source would be nice.

In addition I would like to learn more about the "collisionResolutionSteps_"
A value of 12 is used in the hopper tutorial, but is that a general advice?

Thanks for any reply.

Did anyone ever find an answer to these questions? I am currently stuck on this topic!