About Superquadric functionality in CFDEM

Submitted by enzu on Wed, 08/08/2018 - 04:15

Dear CFDEM community,

LIGGGHTS 3.8 goes superquadric now, but the CFDEM (public) currently works only for spherical particles and the superquadric functionality is not available there.

We are considering modelling ellipsoids in a pipe suspension flow. Just an idea that since LIGGGHTS has taken care of the particle-particle interaction for superquadric shape particles (which is the most complicated part), and despite the fluid-particle interaction models in CFDEM (public) are for spheres only (so won't be perfectly accurate), I am curious is it possible to couple CFD with superquadric shape particles using CFDEM (public) and treat superquadric particles as spheres when considering fluid-particle interaction?

Seems most models in CFDEM require the "radius" parameter from spherical particle. Is it possible (or may take great efforts) to implement this for superquadric particles in the current framework? Thanks.

Cheers,
Enzu

Forums:

Rachel | Wed, 08/08/2018 - 06:19

Hi Enzu,

I don't have any experience with this function combining the superquadric and CFDEM function, while I think this should work if you consider an equivalent sphere for the CFDEM part. This may need some validation and hope you will have a progress soon.

Best,
Rachel

paul | Mon, 08/13/2018 - 20:56

This should be easily done (out of the box, at most minor modifications), if actual particle rotation and shape/orientation-dependent drag force are not to be considered.

-> voidfraction calculation and field mapping would be way off.

However, what would be the benefit of this? I'd guess that using the current CFDEMcoupling-PUBLIC functionality + superquadric DEM would only be viable for system, where the fluid flow doesn't matter that much, but accurate bulk calculation matters.

vsivasan | Thu, 05/28/2020 - 07:26

Hi,
I have been trying to study the motion of the ellipsoidal particle in a fluid particle. I initially tried to figure out the same for spherical particles which I was able to do. However, when I tried to implement this for superquadric particles I get the following error:
ERROR on proc 0: Using default surface model for non-spherical particles! (../surface_model_default.h:144)
 (../surface_model_default.h:144)
Then I came across this forum, Is it true that superquadric particles are not included in CFDEM Public version. Could anyone please clarify this? If by any chance, this has been made available, could anyone please guide me on how to deal with this error. Any help would be appreciated.

Thanks,
Vishal S Sivasankar

Kashminder | Thu, 12/02/2021 - 20:28

I was wondering if anyone can share the structure of the data file or the actual data file for superquadric particles