Experimental procedure and database for non-Newtonian open channel flow

Abstract

Unlike Newtonian open channel flow, not much work has been done to study the flow behaviour of non-Newtonian fluids in open channels.A scarcity of water worldwide has forced design engineers to increase the solid concentrations when designing flumes. With this increase in concentration, the fluids become more non-Newtonian in behaviour. Very little data have been available to test some of the design protocols that have been proposed by various authors (Kozicki and Tiu, 1967;Wilson, 1991; De Kee et al., 1990). Limited amount of data have been published by some authors (Coussot, 1994; Naik, 1983) to test their own protocols. Haldenwang (2003) at the Flow Process Research Centre of the Cape Peninsula University of Technology created a large experimental database for non-Newtonian open channel flow. The experiments were carried out in three rectangular tilting flumes of different widths varying from 75 to 300 mm. The tests were conducted on three fluids: bentonite and kaolin suspensions and carboxymethylcellulose solutions, all at various concentrations. Rheological characterisation of the fluids were conducted in an inline tube viscometer with three different diameter tubes. This paper will describe the methodology behind how the data were obtained for the database. It is hoped that the database will be of use to researchers working in the area of non-Newtonian open channel flow.