RÉSUMÉ

The surface-wave induced boundary-layer flow field over a fixed ripple bed was studied using particle tracking velocimetry. The surface wave phase-dependent mean velocity and vorticity fields are presented for one-half wave period (the system is essentially, although not exactly symmetric) showing the vorticity generation and ejection process. The wave-induced streaming (mass flux) profile is determined and its implications discussed. The Reynolds stress, turbulence production, and turbulent kinetic energy at a single phase are presented and discussed.