Experimental Investigation of Droplet Distributions from a Plunging
Breaker with Different Wind Conditions
Abstract
Understanding the droplet cloud and spray dynamics is important on the
study of the ocean surface and marine boundary layer. Several of the
relevant phenomena depend highly on the characteristics of the spray
produced by waves. Nonetheless, the role that the wave energy and the
type of wave breaking plays in the resulting distribution and dynamics
of droplets is yet to be understood. The aim of this work was to
generate violent plunging breakers in the laboratory, quantify the
produced droplets, obtaining their sizes and dynamics and to analyze the
effect of the different wind speeds on the droplet production. It was
found that the mean radius increases with the wave energy and the shape
of the initial distribution of droplet sizes does not change with the
presence of wind. Also, indications of turbulence affecting the droplet
dynamics at wind speeds of 5m/s were found. The amount of large droplets
(radius > 1mm) found in this work was larger than expected
from the literature. An improved estimation of the initial distribution
of large droplets can largely affect the evolution of the Sea Spray
Generation Function, and therefore the estimation of energy and mass
transport in the marine boundary layer.