Purpose. The purpose of the work is to investigate the impact of the longitudinal profile of air flow velocity on the evaporation process, and to consider the accelerating, uniform and decelerating air flows.

Methods and Results. The process of evaporation from the water surface blown by wind, the speed of which varied within the range 0.68–7 m/s was studied in the laboratory experiments. The latter were conducted in a direct wind-wave channel at different wind field configurations conditioned by the choice of installation parameters. An open channel and a channel partially covered with a removable roof were used. The sloping roof and the preset air flow speed made it possible to obtain the accelerating, uniform and decelerating air flows. The volume of evaporated liquid was determined at the fixed values of air flow speed, water and air temperature, water surface temperature, and relative air humidity. The evaporation rate was defined from a flat water surface and in the presence of wind waves, the steepness of which varied within the range 0.1 < ak < 0.31.

Conclusions. It has been established that the rate of evaporation from a flat surface at a decelerating air flow significantly exceeds those recorded at the uniform and accelerating ones. When wind waves are in a decelerating air flow, the evaporation rate increases with the growing wave steepness. The evaporation is additionally enhanced in case the capillary waves are present on the front slope of nonlinear wind waves.