Author(s): Hitoshi Miyamoto; Akira Kadota; Kouichi Morimoto
Linked Author(s): Hitoshi MIYAMOTO
Keywords: Hydraulic bore; Bottom friction; Momentum conservation; Laboratory experiment
Abstract: In this study, we analytically and experimentally investigated propagation characteristics of a hydraulic bore in a rough bed open-channel, and attempted to model the bed friction effect. Momentum conservation was used to derive an equation for the propagation velocity, in which both the frictional and gravitational forces were taken into account. A laboratory experiment was carried out to develop a bottom friction law applied to the bore propagation. The friction coefficient was obtained as an extension from that for a steady-state open-channel flow, and was set to be a function of the channel slope and the water level difference around the bore head. As the water level difference decreased and/or the slope increased, the coefficient became small and converged to the steady-state value in the limit. The results obtained in this paper indicated that the bottom friction effect was one of the important components to describe the bore propagation in an open-channel with a rough bed.
Year: 2011