DCIV measurements of flow fields and turbulence in waves breaking over a bar

The experimental investigation of laboratory waves breaking over a bottom topography resembling a bar is presented in this paper. The experiments were conducted in a glass flume. The instantaneous velocity fields were measured using a video based digital correlation image velocimetry (DCIV). Measurements of velocities were restricted to positions shorewards of the bar crest. Measurements of time averaged velocities, turbulence intensities and turbulent kinetic energies that span the entire water column are provided. As the plunging-like wave at the crest of the bar turns into a spilling-like wave with increasing depth on-shore of the bar, it is shown that a limited transfer of TKE down to the bed is observed compared to spilling breakers on uniform slopes.