Hydrodynamic Aspects of Drag Reduction with Additives

Abstract

The hydrodynamic aspects of drag reduction with additives are presented. The fundamental properties of this remarkable phenomenon are described. A brief history is outlined from anomalous results in pipe flow, through strange effects in the Texas oilfields and to the current research efforts. Correlation by means of the velocity similarity laws of turbulent flow is explained for drag reduction in pipe flow and for the boundary layers on bodies. The limits of drag reduction are also explained on the basis of the interactive similarity law. The peculiar role of viscoelasticity is examined. Naval architectural applications are reviewed.