An Experimental setup for combined wave-current flow interacting at a right angle over a plane beach

Abstract

In the present work an investigation on combined wave-current orthogonal flow over a planar beach is presented. A series of tests have been carried out in an experimental tank, in which a wavemaker coupled with a flow recirculation system allows the superposition of an oscillatory flow over an orthogonal steady current. Waves and current interact over a fixed smooth bed with a 1:25 sloping profile. Current only and wave plus current tests have been performed, during which surface elevation and velocity profiles measurements have been recovered. Velocity measurements have been carried out at different positions in the tank in order to investigate effects on the velocity profile determined by presence of the sloping bottom at different depths. Results of current only tests showed that a satisfactory steady current is achieved within the tank, although presence of a minor recirculation effect determines a mean flow to arise in the direction orthogonal to the current. Superposition of waves determines a mean momentum transfer on current, which results in an increased current velocity and a reduction of the recirculation effect.