Experimental Study of Flow Division in a Smooth Circular Culvert

The idea of partitioning the flow has been widely used by hydraulic researchers and engineers. Currently, researchers claim that their models for the division lines are valid and yield good agreement with the experimental data from a channel flow that has a flat bed. It is not clear whether their models are still effective to model the division lines when the channel bed is curved. The aim of this paper is to examine the existence of division lines by analysing the distribution of mean velocity in a smooth culvert. The experiments reported here document a sufficient fact that it possible to observe the division lines from the velocity distribution. The method used to test the existence of the division line is to determine the normal distance from a boundary L-n, based on the local boundary shear stress. The model from Yang and Lim (YLM) is selected for considerations in this comparison because other models were unable to produce the theoretical division lines in these cases. The division lines obtained from YLM are also plotted for various experimental flows to demonstrate the relationship between the experimental and theoretical division lines. This experimental analytical method developed for division lines may be extended to any arbitrary channels in other channel flows based on the results of the distribution of velocity.