Numerical Simulations on the Capsizing of Bulk Carriers with Nickel Ores

Abstract

The liquefaction of nickel ore is widely considered to account for the capsizing and sinking of bulk carriers, but the mechanisms that lead to the incidents still remain uncertain. In this paper, the sloshing motion of fluid with high viscosity in a rectangular tank has been studied; the Level Set Method has been employed to predict the behaviours of fluid sloshing motion under the circumstances of beam seas. In a bid to evaluate the consistency of the numerical solution, a full validation has been performed. The results obtained from the simulations are in good agreement with that from the experiment. The conclusions have also been made that the collapse of the shear resistance of the fluid or increasing heeling moment acquired from the fluid sloshing after liquefaction of the nickel ore may be responsible for the capsizing and sinking of the ships. Hopefully, our conclusions can help ship owners better understand how to take precautions to prevent the ships from capsizing while carrying nickel ore or similar cargos; the results could provide the IMO with the theoretical basis for stipulating new international safe standards for bulk carriers; the numerical methodology can also help engineers to predict sloshing motion of viscous fluids.