Characteristics of hydraulics jumps over rough horizontal beds

Abstract

The available knowledge on the behaviour of Hydraulic jump is only for smooth, horizontal channel beds and very limited studied have been reported in literature on the performance of hydraulic jumps on rough beds. This research attempts to investigate on the characteristics of hydraulic jumps formed on rough, horizontal channel beds under different flow conditions. A series of laboratory experiments were carried out in a rectangular flume which consists of artificially roughened beds formed by placing rectangular wooden strips in specific intervals. The hydraulic parameters such as, initial water depths, sequent water depth, and flow rate were measured for different bed roughness. The analysis of experimental data showed that the rough bed reduces the distance to the jump from the gate and the sequent depth ratio than in those smooth beds while creating a high energy loss. With the availability of large number of experimental data on hydraulic jumps over rough channel beds, theoretical formulations were developed to express the hydraulic jump characteristics relating roughness parameters such as; roughness density and roughness height.