Experimental study of wave-induced mass transport

An original method is proposed to extract drift velocity induced by waves propagating in a wave flume. The particle image velocimetry technique is employed to measure velocity fields under regular gravity waves propagating at a constant depth. Based on the measurements, the Eulerian mean current velocity is determined. The instantaneous velocity fields are integrated to calculate particle trajectories and the Lagrangian time-averaged vertical distribution of mass-transport velocity. The Stokes drift velocity is determined by subtracting the Eulerian mean current from the Lagrangian mass-transport velocity. The results are in good agreement with theoretical second-order irrotational solution and confirm applicability of the weakly nonlinear solution for calculating transport processes associated with propagating ocean waves.