Numerical simulation of a periodic circulating fluidized bed of binary mixture of particles: Budget analysis

Solène Chevrier (1) , Pascal Fede (1) , Olivier Simonin (1)

1 IMFT - Institut de mécanique des fluides de Toulouse

Detailed sensitivity numerical studies have shown that the mesh cell-size may have a drastic effect on the modelling of circulating fluidized bed. Typically the cell-size must be of the order of few particle diameters to predict accurately the dynamical behaviour of a fluidized bed. Then the Euler-Euler numerical simulations of industrial processes are generally performed with grids too coarse to allow the prediction of the local segregation effects. A filtered approach is developed where the unknown terms, called sub-grid contributions,have to be modelled. Highly resolved simulations are used to develop the model. They consist of Euler-Euler simulations with grid refinement up to reach a mesh independent solution. Then spatial filters can be applied in order to measure each sub-grid contribution appearing in the theoretical filtered approach. Such kind of numerical simulation is very expensive and is restricted to very simple configurations. In the present study, highly resolved simulations are performed to investigate the sub-grid contributions in case of a binary particle mixture in a periodic circulating gas-solid fluidized bed. A budget analysis is carried out in order to understand and model the effect of sub-grid contribution on the hydrodynamic of polydisperse gas-solid circulating fluidized bed.

Mots clés: Gas-solid flow; Circulating fluidized bed; Polydisperse mixture; Filtered approach; Subgrid drag force; Particle-particle collision

Domaines: Mécanique des fluides [physics.class-ph]

Solène Chevrier, Pascal Fede, Olivier Simonin. Numerical simulation of a periodic circulating fluidized bed of binary mixture of particles: Budget analysis. 9th International Conference on Multiphase Flow (ICMF 2016), May 2016, Firenze, Italy. pp. 1-6. ⟨hal-01715388⟩