question for drag force

Submitted by SongDaZ on Thu, 05/26/2016 - 08:50

Hi~ i have a question for drag force.

nowdays, i study a simulation flow about liggghts, especially, coupling with openfoam.

i want to find how to affect flow( liquid or gas) to particle. so, i look at files for coupling(fix_cfd_coupling.cpp, fix_cfd_coupling_force.cpp and so on)

I found a drag force add to orient force(f[]) in function post_force(int).

but i could not find how to calculate dragforce( fix_dragforce_->array_atom).

Where is this force calculated?

thx for read my question, with my odd(?) english.

alice's picture

alice | Wed, 06/01/2016 - 15:55

Hi SongDaZ,
the calculation of the drag forces (and others) is carried out by the force models (CFDEMcoupling/src/lagrangian/cfdemParticles/subModels/forceModel). Have a look at the *.C-files of the respective model.
Best regards,

Safaei | Fri, 01/10/2020 - 13:50

Hi Alice,
for a single particle immersed in a fluid how can we calculate the drag force by integrating the pressure distribution (resolved particle) over the particle? (not modelling the forces using coefficients). I think that it must be a postprocessing task. Is there a better idea?