A particle drift model was developed for precise prediction of spilled oil transport at sea surface. The developed model considers the major factors which affect the floating oil movement. For the mechanical oil spreading, Fay's model, which was widely used but described in Eulerian manner, is modified to meet the particle expression in the new model. The new model also includes effect of turbulent diffusion, tidal current, ocean current and wind-driven current.
To verify the model, hindcast simulations were applied to the actual oil spill incidents. They include Hebei Spirit oil spill incident which occurred offshore from the Taean coast in South Korea in 2007, and also Diamond Grace incident which occurred in Tokyo bay in 1997. In the hindcast study, the horizontal turbulent diffusivity was discussed. It was found that the horizontal turbulent diffusivity model introduced in the model can be applicable to the observation results and provides better agreement to the observation than the large eddy simulation.
A controversial point on how to model the wind-driven drift effect in the simulation was also discussed. A numerical method, in which the wind-driven current is numerically solved, was applied to the oil spill simulation. It was found that the vertical mesh as fine as 1m at the sea surface is not still enough for resolving the precise surface current velocity required for the oil spill simulation. To the contrary, the wind coefficient method, which is used in our simulation model, was found to have good reproduction of actual oil spills and more suitable for the practical real-time simulation.
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