[Dommy]

Dear Foamers!

I'm working on Euler/Lagrange validation cases at the moment.
While looking into Disoersion Models I discoverd something in the Code - SMALL, GREAT and ROOTVSMALL.

Some examples (from /openfoam211/src/lagrangian/intermediate/submodels/Kinematic/DispersionModel/GradientDispersionRAS/GradientDispersionRAS.C)

 
scalar sigma = sqrt(2.0*k/3.0);
vector dir = -gradk/(mag(gradk) + SMALL);

 else
    {
        tTurb = GREAT;
        UTurb = vector::zero;
    }

const scalar epsilon =
        this->epsilonPtr_->internalField()[cellI] + ROOTVSMALL;
    const vector& gradk = this->gradkPtr_->internalField()[cellI];

In order to completly understand what I'm doing I need to know what this model is doing. Thanks a lot in advance!

Best,
Thomas