(133b) Superquadric Particle Method for Non-Spherical DEM Simulation in Open Source Mfix: Development, Implementation and Verification

Modeling and simulation of non-spherical granular systems is not only of academic interest but is also highly relevant for many industrial applications. Superquadric particle representation is a general and efficient way to model non-spherical particle as it can be described by beautiful mathematical expression. Also, most of the shapes (such as sphere, prolate, oblate, box, cylinder) can be easily modeled by only varying five shape parameters. This work presents the development, implementation and verification of superquadric particle method in open-source parallel CFD code MFiX, which enables new capability of the MFiX-DEM solver for non-spherical particle simulation. To reduce the computational cost of particle-particle contact detection, both bounding sphere and oriented bounding box (OBB) are employed as broad phase contact detections before entering the narrow phase contact detection. Non-linear force model with considering the equivalent radius of the particle shape curvature is used to better calculate the contact forces. Quaternions theory is implemented to model the superquadric particle orientation and the rotation between global coordinates and local coordinates. The superquadric particle DEM solver are verified and validated by extensive test cases, including particle falling, static packing, hopper discharge, etc.