Numerical Simulation of Submerged Hydraulic Jump Using a Urans Model

This paper presents numerical simulations of the submerged jump of the flow passing under a sluice gate. The 2D unsteady Navier–Stokes equations are solved with the \(k{-}\omega\) SST (Shear Stress Transport) turbulence model. The volume of fluid method is used to compute the free surface and the water–air multiphase flow. The numerical model is applied to an experimental case. The mean flow and turbulence structures of the submerged jump are obtained, and their longitudinal decays are estimated. The computed results agree well with the measured data. The peak streamwise mean velocity and the Reynolds stress decays in the longitudinal direction, mainly accelerated by the adverse pressure gradient. However, the presence of the vena contracta clearly affects the decays of the mean velocity and the peak Reynolds stress downstream of the sluice gate.