Research on shipping energy-saving technology: Hydrofoil amphibious vehicle driven by waterjet propulsion

Abstract

The shipping industry is one of the crucial sources of carbon emissions. With carrying capacity both on land and water, the hydrodynamic characteristics of amphibious vehicles are essential indicators of energy saving and emission reduction. The hydrodynamic characteristics of an amphibious vehicle driven by a single waterjet propulsion are investigated in this study, together with the impact of the NACA0012 hydrofoil mounted at the bow and stern. Based on the RANS and body force methods, the hydrodynamic calculation models of the bare hull and waterjet-driven hull are established. All CFD calculations are based on STAR-CCM+. Based on the towing experiment, an uncertainty analysis is conducted to confirm the precision and legitimacy of the numerical calculation approach. The thrust deduction characteristics of vehicle hulls with different hydrofoil models are analyzed respectively. Small or negative thrust deductions always occur at medium and high speeds. Combined with the analysis of vehicle attitude, flow field, and pressure distribution, the inherent thrust deduction characteristics of the amphibious vehicle and the influence of hydrofoils are studied. Then, the hydrodynamic characteristics of different configurations are compared. The lift characteristics of hydrofoils and their influence on the vehicle's attitude and resistance are studied. The change in the performance of the stern hydrofoil caused by the waterjet propulsion is analyzed. Results show that the hull with two hydrofoils has the best drag-reduction effect when Fr<1.43, and the highest drag-reduction rate is 25.7%.