Drift Current on Water Surface with a Film of Hydrophobic Particles under Uniform and Decelerating Airflow Conditions

The influence of a water surface film composed of hydrophobic particles on the development of drift current under the effect of wind is investigated. In a uniform airflow on a flat water surface, the drift current is caused by viscous forces and increases along the fetch. The formation of stationary waves on the drift current has been observed when the drift velocity U-dr exceeds 0.23 m/s. In a decelerating airflow, in the presence of wind waves, the total component of the drift velocity U-sum cyclically increases and drops until it reaches the viscous component upon a steep wind wave breaking into longer linear waves. As the particle settling time T-s increases, the maximum ratio of the wave component of the drift velocity to the total component U-w/U-sum decreases from 0.6 for clear water to 0.3 for T-s = 4 days.