Numerical simulation of multiphase oil behaviors in ice-covered nearshore water

Abstract

There has been an increase in marine transportation in cold regions, which in turn has led to an increasing risk of oil spills in these areas. To better support risk assessment and pollution control of oil spills, it is important to have a good understanding of oil transport in the environment. This information is essential to manage response priorities and help prepare contingency and mitigating measures. This study aims to simulate 3D wave propagation in shallow water with different broken-ice aerial coverage percentages to assess the fate and transport of oil spill in a nearshore area under different conditions. Based on the Reynolds-averaged Navier-Stokes momentum equations for an incompressible viscous fluid and the Volume of Fluid (VOF) method that is coupled with Six Degree of Freedom (6-DOF) model, a 3D numerical model of three-phase transient flow was developed. It was found that the presence of ice makes the spreading of spilled oil slower in the horizontal direction since the ice can build natural barriers to oil movement. The higher the ice concentration, the slower spilled oil migrates in all directions. The maximum oil volume fraction varies with increasing ice coverage on the water surface area. The wave frequency, the averaged flow velocity, and oil properties affect the oil spread extent and the oil volume fraction. The dumping effect of the wave due to the presence of ice makes the impact of this factor less critical than those in open water.

Keywords: CFD; Ice-covered water; Nearshore; Oil spill; Oil transport.