Periodic longitudinal flows of pseudoplastic materials

Abstract

A model is studied in the full range of all operational parameters of the unsteady plane flow of a power-law liquid induced by periodically variable pressure drop and oscillatory motion of the walls of a plane duct. Using the theory of similariry criteria of the asymptotic behaviour are formulated in four qualitatively different rheodynamic regimes. Corresponding asymptotic expressions are found for the degree of mechanical liquidization by the action of oscillatory shear stress superimposed on the principal steady state component. Theoretical results are illustrated using a set of experimental data on the gravitational flow along a vertical oscillating sheet.