Experimental Study of the Ratio of the Conjugate Heights of the Hydraulic Jump Evolving in A Rectangular Channel of Composite Section with Rough Major Bed and Positive Slope

Abstract

Hydraulic jump is a phenomenon commonly observed downstream of dams, serving to dissipate hydraulic energy or in water transport channels to raise the level of the watercourse. It is characterized by a rapid transition from a supercritical flow state to a subcritical state, leading to considerable energy dissipation. This paper aims to study and analyze the conjugate heights of the hydraulic jump in a rectangular channel with a composite section, characterized by a uniform rough major bed and a positive slope, under diverse flow conditions through experimental research. A series of experiments were conducted in a rectangular channel featuring artificially rough beds composed of homogeneous plastic granules. Hydraulic parameters were measured for different bed roughness and positive slopes, such as the two conjugate heights, initial h₁, final h₂, and flow rate. Analysis of the experimental data showed that the rough major bed and the slope of the channel have an effect on the ratio of the conjugate heights. With the availability of a large amount of experimental data on hydraulic jumps on rough channel beds, mathematical experimental approaches have been obtained to express the Y ratio of the conjugate heights of the hydraulic jumps as a function of roughness and slope parameters.