Particle-particle drag (pure angular flow)

Hello,everyone!
Now I use DEM method to calculate two kinds of pure solid particles. Do I need to consider the particle-particle drag force ?

DEM calculates all the particle-particle collisions, so no.

Thank you for your help!@onlyjus
I have a question to ask you. Do you know how to output the solid phase Angle velocity of DEM particles to the grid in MFIX?@onlyjus

Please see this posting Rotating drum(Angular velocity of particles in a grid cell) - #4 by Zhangxutong where the question about angular velocity has already been answered.

Hello @cgw
You didn’t understand what I was asking.I want the angular velocity data in the “Cell data”.
In vtk_out. f file, dem particle solid velocity can be imported into the"Cell data".

This is not supported. You will need to implement it yourself. Thank you @cgw for taking the time to provide assistance.

Thanks for your reply!@jeff.dietiker @cgw
I’ve tried a lot of things but it failed.Do you know how to do that? @jeff.dietiker Thank you!

I am guessing you want an averaged angular velocity. For each fluid cell, loop over all particles located in that cell and take the average of the angular velocities. Save the result in an array and output it into a vtu file. This will require knowledge of MFiX data and code structure.

Note that if you don’t need the information for each cell, the Monitors will allow you to record the average angular velocity over any user-defined region.

Thank you for your reply! @cgw
I’ll give it a try.