Flow of Complex Fluids Through Packed Bed

The flow of complex fluids through packed bed of particles has great importance in chemical and allied industries. Pressure drop-flow rate behavior is an important consideration while designing fixed bed systems. This article critically reviews the literature available on flow of Newtonian, inelastic and viscoelastic fluids (both shear thinning and constant viscosity elastic fluids) through a fixed and fluidized bed of particles. The existing literature shows contradictory results on pressure drop-flow rate behavior in terms of drag enhancement/drag reduction and homogeneous/non-homogeneous fluidization for the flow of viscoelastic fluids through fixed and fluidized beds, respectively, which demand further investigations to produce reliable data bank. Therefore, experiments were also conducted to study the pressure drop-flow rate behavior for the flow of Boger fluids (constant viscosity elastic fluids) through fixed bed of spherical particles. The effect of fluid elasticity on frictional pressure drop has been elucidated. For the purpose, aqueous solutions of Polyacrylamide (PAA) and Glycerol (80:20 ratio by volume) in the concentration range of 0.01–0.04% (wt./volume) were used as test fluids. Test fluids were characterized in terms of physical and rheological parameters. Preliminary investigations suggest that the pressure drop per unit bed length exhibited asymptotic behavior with variation in Weissenberg number (We) depicting the dominance of elastic effects over inertial effects with increasing We and the dominance of inertia over elastic effects at higher Reynolds numbers. The generated data could be of great use in the field of enhanced oil recovery.