Xiaoxue, J. S., Wang; Qinghong, Zhang; Baoli, Shao; Huilin, Lu. "Granular restitution coefficient-based kinetic theory computations of bubbling fluidized beds," Powder Technology Vol. 394, 2021, pp. 825-837. https://doi.org/10.1016/j.powtec.2021.09.018. (https://www.sciencedirect.com/science/article/pii/S0032591021008081)
Abstract: The coefficient of restitution (CoR) is an empirical parameter in dense gas-particles computational fluid dynamics (CFD) by means of kinetic theory of granular flow (KTGF). A great sensitivity of CoR on predictions was found because of the existence of multiple collisions of particles in fluidized beds. In present study, an empirical correlation of granular CoR is proposed using a coupled KTGF of Euler granular phase and the discrete element method (DEM) of Lagrange discrete particles. The CoR is calculated using statistical methodology according to relative velocity of two colliding discrete particles. The granular CoR is computed from granular volume fractions, indicating that the multiple collision effects on momentum conservation over collision at high granular volume fractions. The granular constitutive equations for the transport coefficients are solved according to granular CoR. The simulated bed expansions agreed with experimental measurements. The predicted granular pressure and viscosity are compared with measured data.
Keywords: Granular coefficient of restitution; Discrete element method; Kinetic theory of granular flow; CFB-KTGF-DEM method; Fluidized bed