Simulating Superellipsoids in DEM Engine

[Mahmoud Yaseen]

Hello All,

Currently, I am working on simulating superellipsoids collisions in a free fall into a cylinder tank. As far as I know, DEM engine can deal with shperical shapes. I would like to hear your suggestion on how to proceed with defining superellipsoids in DEM engine?.

Thanks

[Ruochun Zhang]

There are quite a few demos that feature ellipsoidal shapes in DEM-Engine (Centrifuge, Plow, RotatingDrum...), which can be used as starting points. I'd suggest you try those out and see how ellipsoidal particles are defined in them via "clumping" together spheres of different sizes. Then you can tweak the sphere composition to make them look more like superellipsoids, like adding some outer-ring small spheres to account for the sharp edges.

This is probably the easiest. I do understand that sphere clump does not naturally extend to super-ellipsoidal shapes due to the fine features; this is not even fair for the sphere-clump approach as the tools that use functional shape representations favor superellipsoids exactly because they happen to be a clean mathematical. If you indeed need more accurate super-ellipsoidal shapes in DEM-E and you won't need a huge number of particles, then there are methods to systematically create clumps that represent a volumetric mesh, or even sphere-decompose methods that use a large number of spheres to represent a fine surface mesh, both of which can be used in conjunction with DEM-E. But we can discuss these advanced approaches if you are sure you need them.

Thank you,

Ruochun