Influence of Wall Strain Rate, Polymer Concentration and Channel Height upon Drag Reduction and Turbulent Structure.

摘要

The study investigated fully developed, low polymer concentration, drag-reduced flows in two dimensional channels. Water flows at equal wall shear stress were also measured for comparison with the drag--reduced flows. The first objective of this study was to determine the dependence of drag reduction and turbulent structure upon wall strain rate, average polymer concentration and channel height. The second objective was to test a scale-up procedure for predicting drag reduction in one channel based on results in another channel. Keywords: Drag reduction; Turbulent wall flows. (JES)