Numerical Modeling of Internal Flow Structure in Submerged Hydraulic Jumps

This study compares experimental data taken from a submerged hydraulic jump to results from a k – ε and RNG numerical simulation. The internal flow structure of the jump is investigated by comparing longitudinal and vertical velocity profiles along a vertical direction as well as water surface profiles. The maximum turbulent kinetic energy and longitudinal velocity distribution along the length of the jump are also investigated. The characteristics of the recirculation eddy are investigated by locating the reverse flow in the longitudinal direction. Previous research done on hydraulic jumps has relied on assumptions about the turbulent flow field whereas in this study the turbulence is a part of the solution. The computational grid is based on the experimental set up. The CFD program FLOW-3D was used to simulate the experimental conditions with k – ε and RNG turbulence closure schemes. The results showed that the RNG model performed better in the near bed regions. Also, mean flow conditions returned more quickly in the experiment than either model.