Abstract
The submerged hydraulic jump is a sudden change from the supercritical to subcritical flow, specified by strong turbulence, air entrainment and energy loss. Despite recent studies, hydraulic jump characteristics in smooth and rough beds, the turbulence, the mean velocity and the flow patterns in the cavity region of a submerged hydraulic jump in the rough beds, especially in the case of triangular macroroughnesses, are not completely understood. The objective of this paper was to numerically investigate via the FLOW-3D model the effects of triangular macroroughnesses on the characteristics of submerged jump, including the longitudinal profile of streamlines, flow patterns in the cavity region, horizontal velocity profiles, streamwise velocity distribution, thickness of the inner layer, bed shear stress coefficient, Turbulent Kinetic Energy (TKE) and energy loss, in different macroroughness arrangements and various inlet Froude numbers (1.7 < Fr1 < 9.3). To verify the accuracy and reliability of the present numerical simulations, literature experimental data were considered.
Highlights
IntroductionFree and submerged hydraulic jumps are usually suitable for energy loss under hydraulic structures such as gates, spillways and weirs
Several experimental and numerical studies have been performed on the free and submerged hydraulic jumps over macroroughnesses to foresee how the roughness elements of the bed affect the characteristics of hydraulic jumps compared to the smooth bed
Based on the results drawn from the present study, the agreement between the simulations of this study and the results reported by Ahme following equation for the bed shear stress coefficient on the triangular macroroughnesses
Summary
Free and submerged hydraulic jumps are usually suitable for energy loss under hydraulic structures such as gates, spillways and weirs. The characteristics of hydraulic jumps on the smooth bed have been widely studied [2,3,4,5,6,7,8,9]. Several experimental and numerical studies have been performed on the free and submerged hydraulic jumps over macroroughnesses to foresee how the roughness elements of the bed affect the characteristics of hydraulic jumps compared to the smooth bed. Ead and Rajaratnam [10] investigated the properties of hydraulic jump on sinusoidal macroroughnesses and normalized the water surface profile and discharge with non-dimensional analysis. Tokyay et al [11] observed that the jump length ratio and energy loss over two sinusoidal macroroughnesses were 35% smaller and
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
