On Scale Modeling of Oil Droplet Formation from Spilled Oil

Abstract

ABSTRACT Oil droplets form through various processes when oil is spilled at sea:Breakup of the oil surface layer by breaking waves and intrusion of the droplets into the water column (natural dispersion)Enhanced breakup of the oil layer by application of dispersants (chemical dispersion)Breakup of oil lumps from a subsurface spill by turbulence in the waterEntrainment of droplets from a boomed oil slick caused by a large difference in velocity between the oil and the waterBreakup of oil droplets after disposal of oily water into the turbulent wake of a ship. The formation of droplets from a coherent oil mass has been found to be dependent on a complex structure of process parameters, for example, the turbulent eddy structure in the water, internal breaking waves on the oil-water interface, and viscosity and interfacial tension of the oil. The behavior of oil and oil droplet formation in the above processes can be studied relatively easily in small-scale laboratory models, provided that the scaling rules are understood and the laboratory results can be interpreted in terms of field situations. Several laboratory model studies of oil droplet formation were performed by Delft Hydraulics. Much attention was paid to scaling rules and the reliable interpretation of the results in terms of field conditions. Results and conclusions about the modeling process are discussed.