Fluid Dynamic Study of a Semicylindrical Spouted Bed: Evaluation of the Shear Stress Effects in the Flat Wall Region Using Computational Fluid Dynamics

Abstract

Using a semicylindrical spouted bed to obtain experimental data of cylindrical vessels is an old technique and it has already been widely studied by experimental procedures. In the mathematical modeling of semicylindrical spouted beds, the specularity coefficient is one of the ways of including the effect of shear stress in the solid phase promoted by the flat wall. This parameter can be included in the boundary condition of a semicylindrical spouted bed to represent this friction effect. The main purpose of this paper is to discuss the numerical influence of the specularity coefficient on the fluid and solid dynamics of the semicylindrical vessel. Several numerical simulations were performed using the CFD (computational fluid dynamics) technique, by Euler−Euler 3D modeling, for different parameter values of the specularity coefficient. Experimental pressure data are used to verify these simulations. Numerical and experimental results showed good agreement, and the simulations indicated that particle velocity profiles and solid volume fraction were strongly influenced by the specularity coefficient on the spout channel region. Nonetheless, numerical static pressure and fluid velocity have not presented considerable dependence on this coefficient.