**Abstract Text**
The turbulent airflow over wind generated water waves plays an important role on the air-sea interaction. We present an experimental study of the turbulent flow over wind generated water waves in a laboratory. The experiments were conducted in the wind-wave-current flume at Texas A&M University. Three wind speeds of 6, 8, and 10 m/s, corresponding to the significant wave height of 1.0, 1.5, and 2.5 cm, respectively, were tested. Water surface and instantaneous velocities above the waves were measured using a particle image velocimetry (PIV) system at a fetch of 6.2 m. PIV images were sampled at 2400 Hz with a spatial resolution of 0.125 mm/pixel. The instantaneous velocities were decomposed into a mean, a phase-dependent mean, and a turbulent velocity field. On the leeward side of wave crest, we observed negative vertical velocity and positive Reynolds shear stresses. The opposite signs of these parameters were found on the windward side of wave crest. The turbulent kinetic energy (TKE) budget was also analyzed. While the shear production of TKE was positive on the leeward side and negative on windward side of wave crest, the highest TKE dissipations concentrated close to the wave crest. The TKE budget were generally balanced among shear production, mean flow advection, turbulent transport and dissipation rate with some residues that may be attributed to measurement uncertainty and pressure transport. With increasing wind speed, the shear production and turbulent transport of TKE increased whereas the dissipation and advection were relatively unchanged.



Experimental study of the turbulent flow field over wind generated water waves (Room 322, Tuesday June 27th, 8:30am-10:00am)

Engineers, researchers, and climate scientists share developments and innovative practices in the water engineering industry. The Technical Committee for Hydraulics Measurements and Experimental Methods (TCHMEM) of EWRI has organized the HMEM conference six times since 1994, when the first HMEM conference was held in Buffalo, NY. Since then, successful conferences were held in Estes Park, Colorado (2002), Lake Placid, New York (2007), Snowbird, Utah (2012), and Durham, New Hampshire (2017).