Momentum Considerations in Hydraulic Jumps and Bores

Abstract

A hydraulic jump is the turbulent transition from a high velocity into a slower flow. A related process is the hydraulic jump in translation. The application of the equations of conservation of mass and momentum in their integral form yields a series of relationships between the flow properties in front of and behind the jump. The effects of the cross-sectional shape and bed friction are investigated. The effect of the flow resistance yields a smaller ratio of conjugate cross-section areas for a given Froude number. The solutions are tested with some field measurements of tidal bores in natural channels, illustrating the range of cross-sectional properties in natural systems and irregular channels. © 2012 American Society of Civil Engineers.