Two-Temperature Nonequilibrium Model of a Marine Boundary Layer Laden with Evaporating Ocean Spray under High-Wind Conditions

A nonequilibrium two-temperature multiphase model of the atmospheric boundary layer above wave crests that is laden with evaporating ocean spray in high-wind condition is presented. The governing equations are derived from basic physical principles of conservation of momentum, mass, and thermal energy in multiphase flows. The model derivation uses an Eulerian multifluid approach that considers spray as a continuous medium interacting with the gas phase. The E − ε turbulence closure is used. The developed theoretical framework accounts for the nonuniform ocean spray distribution and the thermal energy exchange between air and spray droplets that, in general, have different temperatures above the wave crest level. Such thermodynamic nonequilibrium conditions are shown to exist when the spray concentration is relatively low and the air humidity is far from saturation. The mechanical and thermodynamic effects of the evaporating spray on airflow and heat transport characteristics are obtained and shown to depend sensitively on the spray concentration.