[ansubru]

Hey everybody!!

I am new to openfoam and I have been having a lot of difficulty in trying to understand and implement the drag formulation. I am trying to simulate a system of particles (dense packing, vol fraction 0.85) in a box. This simulation is an extension of the hopper tutorial (icoUncoupledKinematicParcelFoam).

For a given system, particle gravity is constant but gas drag changes dramatically (in a strong non-linear way) with the local particle number density. The presence of other particles restricts fluid space, creates a sharp velocity gradient in the surrounding gas phase and, as a result, yields increased shear stress acting on the particle surface. This is the effect i want to quantify.

There are several relations in literature to account for expressing drag in the presence of other particles. i would like to implement one/several of these. I am having a hard time trying to figure out in which file/s are the expression for drag force being estimated (I have examined the file Spheredragforce.C in the location ~./src/lagrangian/intermediate/submodels/Kinematic/ParticleForces/Drag/SphereDrag). But this file only provides the expression for the drag coe-eff Cd, what i want is the expression for the drag force Fdrag, which I am unable to locate.

Could anyone help me in identifying this source file??

Regards

ansubru