External Boundary Layers in Aqueous Polymer Solution Flows

Abstract

<p>This thesis describes an experimental study of external boundary layers formed on a flat plate model immersed in dilute homoqeneous polymer solutions.</p> <p> The model was subjected to flows of homoqeneous aqueous polyacrylamide solutions with a free stream velocity of 2.21 feet per second.</p> <p> Variations in the drag force with respsct to solution concentration were assessed from extensive velocity profile data and direct drag measurements. For the flow conditions a maximum reduction in total drag of 33 per cent occurred for a concentration of 50 wppm. Profile drag, as well as viscous drag, is apparently reduced in dilute polymer solutions. For the polymer used, a critical wall shear stress of 0.011lbf/ft.^2 was found below which no reduction in viscous drag occurs.</p>