Fragments spawning and interaction models for DEM breakage simulation

摘要

Particles breakage occurs in many industrial applications. During the last decade many works have been devoted for modelling and simulating such processes. A new and innovative procedure of empirical comminution functions for Discrete Element Method (DEM) simulations (Kalman et al. in Granul Matter 11(4):253-266,2009) posed the question how to introduce the fragments of the broken particle back into the computational domain. Daughter particles (Fragments) spawning and interaction imposes several problems during DEM simulation. Some of the main problems are: seeding (allocating) daughter particles and their initial conditions i.e. fragments locations, velocities and physical properties. This work focuses on the daughter particles seeding and the interaction between "sibling" particles for spherical particles. Fragments spawning and interaction algorithm for particle breakage during DEM simulation was developed. The algorithm enables prediction of particle comminution/attrition processes using DEM applications. The new algorithm can utilize any breakage function allowing unlimited fragment size fractions. In the proposed model, sibling particles can overlap without increasing the energy of the system in the simulation. Particle-particle and particle-wall interactions are calculated using the standard DEM calculations. Daughter particles interactions were calculated using the developed temporary contact radius model. The model was utilized to predict particle comminution in jet milling and particle attrition during pneumatic conveying with great successes.