Multiscale modeling of gas-fluidized beds

As one important example of particle-laden flows, fluidized beds have been the subject of intense research owing to their wealth of scientifically interesting phenomena, as well as their innumerable industrial applications. This chapter presents a condensed summary of the current state of knowledge regarding the hydrodynamics of gas-fluidized bed reactors achieved with the use of the state-of-the-art numerical modeling methods, most of which are already described in previous chapters. The results are achieved by using a multiscale modeling approach, combining particle-level interactions using particle-resolved direct numerical simulations, mesoscale information of particulate flow obtained using computational fluid dynamics – discrete element method type Euler–Lagrange methods, and macroscale overall process effects analyzed using continuum models like two-fluid models with kinetic theory of granular flow. Particular emphasis is placed on studies of drag correlation, cohesive particles, non-spherical particles, and fluidization with liquid injection. At the end of this chapter, we recommend some key areas for future contributions from the perspective of numerical modeling.