Elsevier

Advanced Powder Technology

Volume 29, Issue 12, December 2018, Pages 3368-3374
Advanced Powder Technology

Original Research Paper
CFD simulation of particle segregation in a rotating drum. Part II: Effects of specularity coefficient

https://doi.org/10.1016/j.apt.2018.09.019Get rights and content
Under a Creative Commons license
open access

Highlights

  • Segregation in rotating drums is studied by CFD simulations.

  • Particle viscosity is determined by the bed surface fitting BSF method.

  • Specularity coefficient affects the core/band formation rate.

  • Specularity coefficient affects the segregation structure.

  • A proper specularity coefficient should be used in granular CFD simulations.

Abstract

Segregation of binary particle mixture in a rotating drum is numerically studied using the Eulerian multiphase computational fluid dynamics (CFD) simulations coupling the solid phase kinetic theory of granular flow model. The corresponding solid kinetic viscosities of the two particulate phases are determined by the previous granular bed surface fitting (BSF) method. The effects of the specularity coefficients used in the simulations on the segregation patterns in the rotating drums are systematically studied by using the specularity coefficient values ranging from 0.15 to 1.0. When using a smaller specularity coefficient value in the simulation, the momentum transferring from the drum wall to the particulate phase is poorer, lowering the kinetic energy of the particulate phase. The lower particulate phase kinetic energy causes slower particle motion in the bed and hence delays the segregation core/band formation. At the same simulation time, the concentration of the smaller particles in the segregation core increases with the increasing of the specularity coefficient value used in the simulation. When the specularity coefficient values larger than 0.4 are used in our simulations, the realistic three-dimensional segregation structures are well predicted. A proper specularity coefficient value should be adopted in Eulerian multiphase CFD simulations of granular flows.

Keywords

Specularity coefficient
Segregation
Rotating drum
CFD
Eulerian multiphase modeling

Cited by (0)

Open Access for this article was sponsored by the Society of Powder Technology, Japan, through the KAKENHI Grant Number 18HP2009/Grant-in-Aid for Publication of Scientific Research Results, Japan Society for the Promotion of Science, 2018.