Hydrodynamic simulation and optimization of an oil skimmer

Abstract

Oil spills can cause severe environmental damage. The challenges of removing oil spills in the sea arise when a vessel is operated in heavy sea and current conditions. An oil skimmer has recently been developed by Extreme Spill Technology (EST) Inc. for automated oil recovery by using vacuum mechanism. This thesis discusses numerical and experimental results of the hydrodynamic performance of the oil recovery process conducted by the oil skimmer. The process of oil recovery by the vacuum mechanism is complicated and involves multi-phase and multi-scale moving interfaces, including oil, water, atmospheric air and attenuated compressible air on the top part of the vacuum tower, a moving interface of an oil slick, oil droplets and air bubbles of different scales. The recovery process was simplified into a three-phase flow problem involving oil, water and air and simulated using a Computational Fluid Dynamic (CFD) method. The volume of fluid (VOF) method was employed to capture the moving surfaces between the fluid phases. Numerical results were compared with the experimental data. The research was also extended to optimize the geometry of the tower along with the service speeds of the oil skimmer model for maximizing oil recovery. During this research process, my work was to investigate the numerical simulation of the hydrodynamic performance of the oil skimmer model and to provide the optimized geometries and service speeds based on the results from CFD analysis. The verification experiments were also designed and completed. The successful numerical simulation results for the oil skimmer with the optimized geometry will be beneficial for the field test in the future. The improvements can be made directly to the existing oil skimmer models.