Formation and Vertical Mixing of Oil Droplets Resulting from Oil Slick Under Breaking Waves—A Modeling Study

Migration Movements of Accidentally Spilled Oil in Environmental Waters: A Review

“…Three types of waves, regular waves, irregular waves and breaking waves, are generally involved in the research, which is usually described by wave height, wave length, wave energy, etc. [108][109][110]. The details can be seen in Figure 4.…”

“…Thus, when large quantities of oil are spilled on the ocean in a short period of time, the oil film which first forms is thick so that small ocean waves passing through it tend to be damped out; meanwhile, the film itself appears to ride on any large swells present, at which point the breakup of the film into oil droplets is inhibited [111]. As the oil film continues to spread and become thinner, the high energy and strong vortex generated by the waves' action begins to accelerate the generation of oil droplets [111], increasing the distance between each oil droplet which enters the water column, and also inhibiting the coalescence of oil droplets into large oil droplets to resurface by reducing the frequency of oil droplet collision; the spread of oil droplets and the degree of diving increases until the dynamic stability of vertical mixing is achieved [108,112,113].…”

“…This process involves two main components, the total amount of oil entering the water column and the distribution of oil staying in the water column. Among them, since the oil dispersion volume/rate (sometimes called wave entrainment volume/rate) is directly related to the surface oil slick volume and diffusion movement, etc., most of the current studies focus on quantifying the relationship between wave energy or oil spill characteristics and oil dispersion volume/rate [18,108,113], while relatively little research has been conducted on the spatial and temporal distribution of the concentration of oil in the water column.…”

“…Although this equation is empirical and needs to rely on proportionality constants to correct for different oils, Delvigne's experiments were by far considered the most extensive and the most complete in terms of data and empirical models obtained. Subsequently, Tkalich and Chen used a kinetic model considering only the vertical exchange of oil droplets between the oil slick and the mixed layer, and a more precise parametric description of the wave breaking phenomenon, in order to apply the above model for more diverse environmental conditions [108,138]. To address the situation that previous related studies have mainly focused on oils with viscosities less than 1000 cP, Reed et al extended the oil diffusion model to higher viscosities and even non-Newtonian regions by using the dimensional analysis method and considering both Weber number and dimensionless viscosity groups [121].…”