FLOW CHARACTERISTICS OF SETTLING SUSPENSIONS AND FLUIDIZED-BEDS OF SPHERICAL-PARTICLES

The complete Navier-Stokes equations together with the free surface cell model have been solved numerically to obtain the theoretical estimates of drag coefficients of particle assemblages moving through an incompressible Newtonian liquid. The results reported herein have been expressed in terms of the constant rate sedimentation velocities for concentrated suspensions and voidage-velocity behaviour for particulately fluidized liquid-solid systems. Theoretical results have been validated by carrying out detailed comparisons with the widely used correlations available in the literature. Bearing in mind the experimental uncertainty in this field, the agreement between theory and experiments is satisfactory in the range of variables, (0.3 £ e ^0.9) and (10_3< Re < 100), studied in this work. © 1991, Taylor & Francis Group, LLC. All rights reserved.