Developing laminar flow in curved rectangular channels

Abstract

As an intermediate step between earlier investigations on fully developed laminar flow in curved channels of shallow rectancular wet cross-section and the mathematical modeling of turbulent flow in river bends, a mathematical model of developing laminar flow in such channels is investigated. The most important assumptions made in addition to those based on the fully developed flow investigations are verified for the flow in a rather sharply curved flume with rather strong effects of curvature. Experimental data on turbulent flow are compared qualitatively with the results of an equivalent laminar flow computation for two different flumes. This comparison shows the measured and the computed depth-averaged main velocity distributions to agree well beyond the first part of the bend, which confirms the presumption that the mechanism of the main velocity redistribution in turbulent flow is essentially the same as in laminar flow.Hydraulic EngineeringCivil Engineering and Geoscience