Flow of Non-Newtonian Fluids in Curved Pipes : 3rd Report, Turbulent Friction Coefficient

Abstract

Turbulent friction coefficients are measured for fully-developed flows in curved pipes with a circular and square cross section using non-Newtonian liquids (aqueous solutions of CMC and PAA). Effects of power-index, Reynolds number and curvature radius ratio are made clear. The turbulent friction coefficient for non-Newtonian liquids is lower than that for Newtonian liquids, and becomes larger as the curvature is stronger. Also, the turbulent friction coefficients fall on a single line in terms of R_e(d/R_c)² for circular pipes and R_e(d/R_c)² for square ones. The transition Reynolds number increases as the curvature is stronger.