A new two-phase coupling model using a random fluid fluctuating velocity: application to liquid fluidized beds

Liquid solid fluidized beds are widely applicable two-phase contactors by which solid and liquid phase constantly exchange energy/mass at the interface. In this paper, a new DEM simulation approach to analyse the hydrodynamic behaviour of fluidized beds has been introduced and validated. In this approach, a random liquid fluctuating velocity following a Gaussian distribution is used to simulate the fluid phase. The mean and standard deviation of the distribution were functions of the liquid velocity and bed concentration. The liquid fluctuating velocity was able to produce a random motion of the particle across the entire bed. This new methodology can predict bed expansion and porosity, particle mixing time and velocity as a function of liquid velocity. The simulation results revealed that using DEM only along with the simulation methodology presented in this study suffices to predict the hydrodynamics of a fluidized bed to a reasonable accuracy.