Experimental Study of Wind Interaction with a Wave Induced by a Wave Generator in a Direct Channel

Abstract

An experimental study has been conducted on the effect of wind blowing on a wave induced by a wave generator in a direct channel. It is shown that with a small wave steepness \(ak<0.1\) and wind speed \(W<2.3\) m/s, a drift current is generated on the water surface due to the action of viscous forces. A formula for calculating its velocity is proposed. It has been found that the phase velocity of the wave increases with the emergence of drift current and can be calculated by the formula obtained for linear waves in a flow with a constant velocity shear. With an increase in wave steepness \(ak>0.19\) and wind speed \(W>2.3\) m/s, the formation of a vortex deforming the water surface over the wave crest was observed in the air flow over the wave crest. The vortex destroys the viscous layer, reducing the drift velocity. This also reduces the phase velocity and the length of the wave. A mechanism explaining this process has been proposed.