Experimental Investigation of Emerged Dike Influence on Combined Discharge Structures in Open Channel Flow

Abstract

This paper investigates experimentally the changing of a hydraulic characteristic of combined hydraulic structure owing to the existence of dike structure. Different models of combined structures are used with rectangular gates and rectangular weirs, respectively. Also, the location of the dike structure is considered. A dike is located upstream, downstream, and on both sides of the combined hydraulic structure. Discharge quantity, average downstream water depth, discharge coefficient, and Reynolds number are adopted to describe the alteration in hydraulic behavior of a combined structure. While the relation between upstream Froude number and downstream Froude number, as well as the relation between downstream Froude number with distance, are employed to illustrate the interactive response between dike and combined structure, From the study, the relation between Froude number at downstream and non-dimensional downstream distance as well as the relation between non-dimensional downstream water depth and non-dimensional distance reveal how the dike location effects on water depth and flow velocity, which lead to a change in the type of flow. Here, the dike position is shared in the form of a hydraulic jump at downstream of the combined structure. The experimental data were statistically analyzed to ensure their validity and reliability. The importance of this study is concentrated on how the location of the dike structure is shared in the alteration in the hydraulic characteristics of the combined hydraulic structure, especially the rise in the water depth at downstream, in addition to the change in the hydraulic jump height and energy losses.