XXII ICTAM, 25–29 August 2008, Adelaide, Australia SPACE-TIME MEASUREMENTS OF BREAKING WAVE KINEMATICS AND VOID FRACTION IN THE SURF ZONE

Particle Image Velocimetry (PIV) measurements were performed in a wave tank under regular water waves propagating and breaking on a 1/15 sloping beach. To obtain more accurate measurements, the domain from the initiation of the breaking to the swash zone is splited in fourteen overlapping windows. The full field is reconstructed at each time step by gathering the fourteen synchronized PIV fields. We measured then the complete space-time evolution of velocity field over the whole surf zone. From these data the ensemble-period-average and phase-average components of the flow with their associated fluctuating parts were computed. Moreover using the light intensity of the PIV images and velocity measurements, we estimated the void fraction in each point of the surf zone and at each time step.