The interaction of gravity waves and turbulent channel flow

Modifications of waves due to wave-current interaction and the corresponding modification of the flow properties by the waves were studied. A theoretical model was developed to describe the energy dissipation in terms of measured wave and hydraulic flow parameters. Turbulent kinetic energy production was analyzed as a function of turbulent Reynolds stress and mean and wave-induced velocity gradients. Wave-current interactions were shown to significantly increase rates of wave energy dissipation. The decay of wave energy increased generally as wave steepness and flow velocity increased. Wave-induced velocities were shown to modify mean velocity gradients and existing turbulence quantities. Spectral quantities as well as phase averaged values showed a decrease in wave related activity as depth increased. Results suggested that surface waves extracted energy from the mean velocity gradient to produce turbulent energy that was diffused downward.