Diameter dependence of the cutoff molecular weights of drag‐reducing polymers

摘要

AbstractDrag reduction data of poly(ethylene oxide) obtained in turbulent pipe flows were analyzed. A cutoff molecular weight for drag reduction was determined by correlating the drag reduction effectiveness with polymer molecular weight. Based on a time‐correlation onset concept, this critical molecular weight was found to depend on the pipe diameter and Reynolds number. This effect is examined using available experimental dat