Large Eddy Simulation of a Turbulent Jet in Wave and Current Environment

A large eddy simulation (LES) model in sigma coordinate is developed based on the spatially filtered Navier-Stokes equations to study the hydrodynamic behaviors of a vertical round jet in a wave and current co-existing environment. The time-averaged current profile adding a sinusoidal wave component, which accounts for the wave and current interaction, is imposed at the inflow boundary to generate the wave and current conditions, while the radiation condition combined with a sponger layer is adopted at the outflow boundary to let the waves and current leave the computational domain smoothly. The jet is numerically generated by specifying a mean jet velocity plus 'artificial turbulence' at the jet inflow boundary. The numerical results of instantaneous and mean flow fields agree well with the measurements in the prior experiments, indicating that the developed model is able to reproduce the complex flow structure of the jet in wave and current co-existing environment.