Effects of Bingham Viscosity on Flows in Curved Pipes.

Abstract

Bingham plastic fluid flows through pipes of circular cross sections coiled in circles were experimentally studied. In the investigations, kaoline clay slurries were used as the Bingham plastic fluid. The effects of the Reynolds number Re or the Dean number De on the friction factor λc in the laminar steady flow of the Bingham plastic fluid flowing through coiled pipes were clarified. The apparent Reynolds number Reap, expected to play the equivalent role of Re in Newtonian fluids, was introduced using the similarity law of energy dissipation which was derived from a generalized equation of non-Newtonian fluid. It was clarified that the effects of the curvature of the pipes are greater in the case of greater concentration of the slurry, and that there exists a good correlation between the friction factor and the apparent Dean number Deap (defined according to Reap).