NUMERICAL-SIMULATION OF HYDRAULIC JUMP

Hydraulic jump on a straight horizontal channel with supercritical Froude numbers 2-0 and 4.0 is numerically simulated by solving the Reynolds averaged Navier-Stokes equations. Turbulence is modelled through the k-epsilon closure equations and the mixed Eulerian-Lagrangian description of flow is utilized to overcome the problem posed by moving free boundary. Time stepping is done via fractional step method and pressure is determined from Poisson's equation. Galerkin finite element method with three-noded triangular elements is used for spatial discretization. A detailed study of the internal and external characteristics of hydraulic jump is done and compared with experimental values where possible. Surface roller and recirculation wne are found to play a dominant role in turbulence generation and dissipation.