Application of Rheological Models in Prediction of Turbulent Slurry Flow

Abstract

The paper deals with fully developed steady turbulent flow of slurry in a circular straight and smooth pipe. The Kaolin slurry consists of very fine solid particles, so the solid particles concentration, and density, and viscosity are assumed to be constant across the pipe. The mathematical model is based on the time averaged momentum equation. The problem of closure was solved by the Launder and Sharma k-e turbulence model (Launder and Sharma, Lett Heat Mass Transf 1:131–138, 1974) but with a different turbulence damping function. The turbulence damping function, used in the mathematical model in the present paper, is that proposed by Bartosik (1997). The mathematical model uses the apparent viscosity concept and the apparent viscosity was calculated using two- and three-parameter rheological models, namely Bingham and Herschel–Bulkley. The main aim of the paper is to compare measurements and predictions of the frictional head loss and velocity distribution, taking into account two- and three-parameter rheological models, namely Bingham and Herschel–Bulkley, if the Kaolin slurry possesses low, moderate, and high yield stress. Predictions compared with measurements show an observable advantage of the Herschel–Bulkley rheological model over the Bingham model particularly if the bulk velocity decreases.