Simulation of particle-to-particle interactions in gas solid flows

Abstract

A Lagrangian simulation technique of a non-dilute gas—solid suspension flow is presented. The method is based on the introduction of simulated particle-to-particle collisions during the trajectory calculation of a particle, with a probability which is predicted through an iterative process, since it depends on the local concentration and velocities. This simulation makes it possible to predict dense gas—solid flows, without having to compute simultaneous trajectories. After a description of the simulation principle, we examine the dynamics of a binary collision between spherical particles, including rotation effects. As a test case, a horizontal gas solid pipe flow was investigated at loading ratios up to 20. Results concerning velocity and concentration profiles, as well as pressure losses, are presented. Comparisons are made with the case of dilute flow simulation, revealing that particle-to-particle interactions play a non-negligible role as soon as the loading ratio exceeds unity.