An integrated turbulent simulation and parameter modeling study on sea-spray dynamics and fluxes

Sea spray droplets are generated in the processes of wave breaking and bubble bursting, which has a remarkable influence on the marine surface boundary layer, especially at high wind speed like typhoon. This paper presents an integrated study with Large-eddy simulation (LES) on wind-wave-droplet coupled transport and spray-flux parameterization methods, which includes a sea-spray generation function, a drag coefficient (CD) and a heat flux coefficient (CK). The results show a large magnitude and variation similarity to authorized laboratory data and previous models for 10-500μm droplets. The CD fundamental parameters are not only determined by the droplet number, but also influenced by wave-age & wind-wave Reynolds number. With a comprehensive consideration of the these effects, CD shows a tendency of decrease at high wind speed from 33 m/s, and its maximum value is 1.96×10−3. This phenomenon could be explained by a droplet-induced lubricating layer at air-sea interface. The revised CK trend changes obviously and increases with wind increase. The heat transfer is enhanced 66.4% due to droplet effects at 60 m/s. LES results demonstrated that spray droplets concentrate around effective wave height 15 cm with Gaussian distribution, and the peak concentration increases 3.37 times with wind speed increasing 1.67 times.