CFD-DEM simulations in a gas-solid fluidized bed.

Resumo

A gas-solid fluidized bed consists of mixture of gas-solid in which the particles were suspended by an imposed upward flow. In the present paper, we have carried out two dimensional numerical simulations of gas-solid fluidized bed. CFD-DEM (Computational fluid dynamics-discrete element modeling) approach is used to model two phase flow composed of solid particles and gas inside the fluidized bed. It uses Eulerian and Lagrangian methods to solve fluid and solid particles respectively. Gidaspow drag model is used to model the interaction between gas and solid particles. Numerical simulations were carried out for various inlet gas velocities (75 cm/s to 82 cm/s) for the fluidized bed. The aim of the present work to search for linear waves. It is interesting to note that, the amplitude of disturbances increase with the height. Further, it is observed that growth rate of the amplitude of disturbances is linear for vg = 75 cm/s and nonlinear for vg = 78 to 82 cm/s.