EXPERIMENTAL INVESTIGATION ON UNIFORM AND NON-UNIFORM BOUNDARY LAYER UNDER WAVE AND WAVE-CURRENT COMBINATIONS

Abstract

Flume experiments were carried out in order to study the velocity field in the boundary layer under wave and wave-current combinations. These included both smooth and rough of flat and sloping beds. The particle velocity was measured by an LDV. The particle velocity on the sloping bed was found to follow the logarithmic law of wall as for the flat bed. However, significant differences in the time mean velocity and the mass transport velocity for the combined wavecurrent flows are found. The comparisons in terms of the friction factor and roughness parameter were made with several theoretical models.