Investigation of hydraulic jumps on rough beds with adverse slope: A roughness froude number approach

Abstract

The Bélanger equation has been found to be inadequate for predicting sequent depth in hydraulic jumps occurring on rough, sloping channel beds. To address this limitation, a roughness Froude number incorporating the effects of bed roughness and channel slope has been introduced in this study. Three sets of experimental runs have been conducted in a channel flume using three bed roughness values (0.0256 m, 0.0387 m, and 0.0438 m) and three adverse slopes (-0.025, -0.030, and -0.035). The resulting datasets have been used to tabulate sequent depth and jump length and to develop two regression-based semi-empirical relationships relating the roughness Froude number to the sequent depth ratio and the relative jump length, respectively, for hydraulic jumps on adverse slopes. The proposed equations have been validated against experimental observations and have shown agreement within deviations of 30% for sequent depth and 33% for jump length.