文档介绍：Solved SOL Multiphysics ?SOL 1 | CIRCULATING FLUIDIZED BED Circulating Fluidized Bed Introduction This model simulates the operation of a circulating fluidized bed. In this apparatus the dispersed phase, consisting of solid spherical particles, is fluidized by a gas and transported through a vertical riser. Upon reaching the outlet, the dispersed phase is re-injected in the vicinity of the gas inlet at the bottom of the bed. To study the flow in the fluidized bed, the model uses the Euler-Euler model. The phase properties and model setup follow those in Ref. 1 . Model Definition Figure 1 displays the geometry of the fluidized bed, and schematically describes its means of operation. The fluid phase, consisting of air, is injected at the bottom of the bed. Th e dispersed phase, particles with a diameter of 54 μ m , are fluidized by the gas flow and transported upwards. At the outlet, particles and gas exit the bed. The particles are fed back into the bed through re-injection inlets on the vertical walls near the gas inlet. The dispersed phase flux matches that at the outlet, creating a circulating fluidized bed. Table 1 summarizes the bed geometries and the properties of the phases. The values correspond to those used in Ref. 1 . PROPERTY VALUE Particle diameter 54 μ m Particle density 930 kg/m 3 Gas density (air) kg/m 3 Gas dynamic viscosity (air) ·10 -5 kg/m 3 Gas inlet velocity m/s Bed width m Bed height m TABLE 1: FLUIDIZED BED PROPERTIES Gas inlet Outlet Solid/Gas re-injection Solid/Gas re-injection Solved SOL Multiphysics 2 | CIRCULATING FLUIDIZED BED ?SOL Figure 1: Schematic of the circulating fluidized bed. The geometry is not to scale. GOVERNING EQUATIONS Use the Euler-Euler model to solve for the flow of the continuous and dispersed phase. Both phases are then modeled as rating continua governed by a separate set of Navier-Stokes equations. The model also includes a transport equation for the disp