DETERMINATION OF STABLE HYDRAULIC JUMP CHARACTERISTICS IN A CHANNEL BY USING CFD MODEL

Abstract

Hydraulic jump is an important hydraulic phenomenon for dissipating energy in bottom flows, and it is widely applied downstream of flood discharge structures in irrigation and hydropower systems. As a result, it has received attention very early and has been extensively studied experimentally and theoretically. Although several hydraulic jump characteristics relating to the size design of energy dissipation works, such as conjugate depth, jump length, and energy loss, have been quantified by mathematical formulas, other features of hydraulic jump, such as the flow field, pressure, turbulence flow, energy loss characteristics, and air entrainment, have not either received as much attention or been detailed extensively. Therefore, this study applied the Computational Fluid Dynamics (CFD) method to simulate the phenomenon of a stable, free hydraulic jump on a smooth, horizontal-bottom, rectangular channel, with the supercritical Froude number ranging from 4.61 to 8.97. The research has validated that the numerical model simulated the hydraulic jump phenomenon quite accurately, with an error of less than 5% compared to theoretical calculations and experimental results. The study results have supplemented, completed, and clarified the variations of other hydraulic jump characteristics according to the flow and Froude number, for which experimental or theoretical approaches have been limited. Additionally, the paper results provided valuable references for the energy dissipation hydraulic engineering field.