Modelling and CFD simulation of the trajectory of an oil spill in a large domain: Analysis of the 2003 Foss Barge - Point Wells event

This work proposes a procedure for the Computational Fluid Dynamics (CFD) simulation of an oil spill at a large domain. The use of CFD in a large domain usually has restrictions due to the discretization that is needed for good accuracy. The problem increases as the wind effects over a wavy sea surface must be taken into account. To overcome these difficulties, these effects are included in the boundary conditions, through analytical models or simplified simulations. The effect of the wind is commonly determined by a wind drift factor that estimates the wind induced sea surface velocity as a percentage of the wind speed. In this paper, rather than using fixed or random values for the wind drift factor, a methodology based on CFD simulations of the wind acting over the sea surface is used together with analytical formulations, in order to reduce the subjectivity in its estimation. In addition, to avoid modelling the waves and the air phase, the wind effects are simulated as an equivalent shear stress boundary condition. This procedure is used in the simulation of the Foss Barge - Point Wells oil spill. The results of the oil spill trajectory are compared to the observed trajectory.