Impact velocity-dependent restitution coefficient using a coupled Eulerian fluid phase-Eulerian solid phase-Lagrangian discrete particles phase model in gas-monodisperse particles internally circulating fluidized bed

摘要

A Coupled Eulerian fluid phase-Eulerian solid phase-Lagrangian discrete particles phase model (CEEL) is proposed to study of the hydrodynamics of gas and monodisperse particles in an internally circulating fluidized bed (ICFB). The impact velocity-dependent coefficient of restitution (CoR) used in the kinetic theory of granular flow (KTGF) is determined from the dynamic information of Lagrangian discrete particle phase using discrete element method (DEM). The interphase momentum exchange coefficient between Eulerian fluid phase and Eulerian solid phase gives back to the Lagrangian discrete particle phase. Numerical simulations show that the impact velocity-dependent CoR decreases with the increase of solid volume fraction and impact velocity of discrete particles. The predicted velocities and circulation mass fluxes of Eulerian solid phase and Lagrangian discrete particles phase are close to each other in the ICFB. The granular temperature and rotational granular temperature of Eulerian solid phase and Lagrangian discrete particles phase are predicted. Present CEEL model provides all fields of continuous fluid phase, Eulerian solid phase and the motion of discrete particles in the ICFB. (C) 2018 Elsevier Ltd. All rights reserved.