Experimental Study on Droplet Dispersion over Breaking Wind Waves

Abstract

Sea-water droplets are produced by wave-breaking owing to high wind-shear over the sea surface in a wind-wave tank. The contribution of the droplets to the mass transfer between air and sea has not been clarified. The dispersion mechanism of the droplets was, therfore, investigated under high wind-speed condition with wave-breaking. Droplet diameter and velocity were simultaneously measured using a phase Doppler anemometer (PDA). The results show that the relative velocity between droplet and ambient air depends on the wind-speed and droplet diameter. Horizontal flux of the droplet depends on air friction velocity on the air-water interface, the height from the interface and the droplet diameter. The particle Reynolds number and the horizontal flux of the droplet can well be correlated with these quantities.