Amphibious aircraft have the potential to meet the demands of increasing air transportation by taking off and landing on seas as well as runways. They face engineering design challenges of performing takeoffs and landings on both water and land, with water-takeoffs being relatively more complex for analyses. The reduction of the water-takeoff distance via the use of hydrofoils was a subject of interest in the 1970s, but the computational power to assess their designs was limited. In this thesis, a preliminary computational design framework for hydrofoils is proposed and implemented for the purpose of investigating improvements in the water-takeoff performance of amphibious aircraft. The design framework includes configuration selections and sizing methods for hydrofoils to fit w...[ Read more ]

Amphibious aircraft have the potential to meet the demands of increasing air transportation by taking off and landing on seas as well as runways. They face engineering design challenges of performing takeoffs and landings on both water and land, with water-takeoffs being relatively more complex for analyses. The reduction of the water-takeoff distance via the use of hydrofoils was a subject of interest in the 1970s, but the computational power to assess their designs was limited. In this thesis, a preliminary computational design framework for hydrofoils is proposed and implemented for the purpose of investigating improvements in the water-takeoff performance of amphibious aircraft. The design framework includes configuration selections and sizing methods for hydrofoils to fit within aircraft constraints derived from a flying-boat amphibious aircraft conceptual design for general aviation. The position, span, and incidence angle of the hydrofoil are optimized for minimum water-takeoff distance in consideration of the longitudinal stability of the aircraft in the speed regime of elevator ineffectiveness. The analyses and optimizations are performed by means of water-takeoff simulations, which incorporate hydrodynamic forces such as lift and drag with cavitation effects from the hydrofoil, obtained via 2D computational fluid dynamics simulations to generate surrogate models for reductions in computational time. The design procedure is evaluated in a case study of a 10-seater amphibious aircraft; the results indicate that the addition of a supercavitating hydrofoil design achieves the purpose of reducing water-takeoff distance, which demonstrates its potential to improve the takeoff performance. A detailed design framework for amphibious aircraft considering the relevant constraints is also proposed.