Investigation of Drag Reduction Effects in Turbulent Boundary Layer Flow of Polymer Solutions and Mechanical Degradation during Solution Preparation

Abstract

Some polymers are highly susceptible to degradation caused by mechanical shear forces. This study focuses on the impact of stirring power during solution preparation on the turbulent drag reduction effect. PIV measurements of turbulent boundary layer flow were conducted to clarify the influence of stirring rotation numbers on drag reduction by injecting polymer solutions with different stirring rotation numbers. Extensional viscosity measurements were also performed to investigate the effect of mechanical degrada tion on the rheological properties of the polymers. Based on these insights, we investigated the relation between the mechanical degradation of polymers and their drag reduction effect.