EFFECT OF MOLECULAR WEIGHT AND SEGMENTAL CONSTITUTION ON THE ORAG REDUCTION OF WATER SOLUBLE POLYMERS

摘要

Tube 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.nThe 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.nA 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.