Hydrodynamic Characteristics of a Hydrofoil-assisted Amphibious Vehicle

For amphibious vehicles that are utilized in military services, high-speed ship-to-shore movement is an important requirement for enhancement of the operational capability in tactical environments. At high speeds, such a vehicle begins to sink at the stern, causing the bow to rise out of the water. Moreover, excessive trim has a deleterious effect on forward field of vision and powering performance. In this study, a hydrofoil was considered as a trim-control device to decrease the significant bow rise without compromising the performance. Experiments were conducted in a towing tank to investigate the running attitude and powering performance of a box-shaped amphibious vehicle at high speeds. Results for the hydrodynamic features show that a fixed hydrofoil under the stern of the vehicle successfully achieved an improved trim. It was also found that the interaction between the waterjet and hydrofoil can enhance the dynamic lift of the hydrofoil.