Author(s): Jona Johari; Lars Erik Holmedal; Dag Myrhaug
Linked Author(s):
Keywords: Waves; Currents; Longuet-Higgins streaming; Rough bed; Seabed boundary layer
Abstract: In coastal zones the particle movements induced by surface waves have a strong effect in the entire flow region from the surface to the bottom of the sea. In general, the flow in this region is induced by surface waves and currents. This paper investigates the seabed boundary layer beneath waves following and opposing a current by considering the Longuet-Higgins streaming effect. As a first step the rough turbulent bottom boundary layer beneath waves following and opposing a current has been examined by using a boundary layer model for realistic physical situations and compared with existing laboratory measurements to verify the model. The turbulence closure is provided by a high Reynolds number k-ε model. The mean velocity due to the effect of the Longuet-Higgins streaming for realistic physical conditions in waves alone and waves combined with the current is investigated near the bed. The comparison between model predictions and the Kemp and Simons (1982,1983) data are fairly well predicted near the bed.
Year: 2011