Two- and three-dimensional computational studies of liquid-solid fluidization

The present work Compares the hydrodynamics in the 2-dimension (2-D) and 3-dimension (3-D) liquid-solid fluidized beds using a simple two-fluid model suggested by Brandani and Zhang (2006). This model considers the effect of the particles dispersed on the momentum equations into the inviscid model A of Gidaspow (1994). Numerical simulations are conducted in the platform of CFX 4.4, a commercial CFD code, together with user-defined FORTRAN subroutines. Based on the independence of mesh size and time step in the 2-D bed, detailed hydrodynamics are compared numerically in the 2-D and 3-D beds after a sudden change in the liquid inlet velocity and the physical property of the liquid-solid system. The computational results show that the bed height, surface height and vertical solid holdup profile within the 2-D and 3-D beds are in the good agreement after a decrease in the liquid inlet velocity or an increase in the liquid-solid density difference and liquid viscosity. However, the differences of surface height and vertical solid holdup profile are found between the 2-D and 3-D simulation when the liquid inlet velocity is increased or the particle diameter is decreased. (C) 2012 Elsevier B.V. All rights reserved.