Ke Zhang
Harbin Institute of Technology, China
Title: Polymer induced turbulent drag reduction in a rotating disk apparatus
Biography
Biography: Ke Zhang
Abstract
It is well-known that the skin frictional drag of turbulent flow can be remarkably decreased when tiny amounts of polymers are added. Recently, polymers as turbulent drag additives have been successfully applied in different fields, such as firefighting, oil transportation and farm irrigation. However, they present less resistant to high shear and extensional rates under turbulent flows. In this study, the effect of Reynolds number (Re), temperature, polymer molecular weight, and distribution as well as concentration on the drag reduction (DR) efficiency of copolymers was investigated in a rotating disk apparatus. To explore the regularity of mechanical degradation, DR efficiency was also analyzed as the function of time by using different models such as a simple exponential decay function, stretched-exponential model, and Brostow equation.