Effect of Molecular Weight and Segmental Constitution on the Drag Reduction of Water Soluble Polymers
Author: Gail T. Pruitt
Publisher:
Published: 1965
Total Pages: 125
ISBN-13:
DOWNLOAD EBOOKTube flow data on some 16 polymers indicate that drag reduction is a function of molecular contour length, segmental side groups, concentration, pipe diameter and Reynolds number. The maximum drag reduction actually obtained with any drag reducing polymer is approximately 80% of that which would be obtained if completely laminar flow was maintained. A relationship that correlates drag reduction, concentration and molecular dimensions is suggested for a constant Reynolds number and pipe size. It infers that a critical concentration of polymer exists, below which no drag reduction occurs. Also for some given concentrations and pipe size a critical velocity exists below which no drag reduction occurs. Rheological data for two polymer solutions are presented in terms of elastic energy. (Author).