Application Research Of Hydrofoil In Wing-In-Ground Effect Craft

Wing-In-Ground-Effect(WIGE) craft has drawn attention from all over the world due to its attractive development potential. But the big drag during takeoff has become the bottleneck of its development. In order to improve the take-off performance, a hydrofoil is applied to the WIGE craft according to the concept of hovercraft design. The research on hydrofoil application in WIGE craft is presented in this thesis as follows:a) The background of hydrofoil application in WIGE craft was introduced; the preliminarily design of the hydrofoil configuration was carried out, and then optimized in the ISIGHT, a Multidisciplinary Design Optimization(MDO) software.b) A decoupled aerodynamic and hydrodynamic combined with the kinematics equation method was utilized for simulating take-off on the water of WIGE craft. Both the take-off process of WIGE craft with hydrofoil and WIGE craft without hydrofoil but with fuselage of seaplane were calculated for the curve of drag versus velocity and the take-off distance. The results indicate that the maximum drag of the WIGE craft with hydrofoil is reduced by 31.6% comparing with the WIGE craft only with fuselage of seaplane, and the take-off distance of the WIGE craft with hydrofoil is also reduced by 39.2%.c) The aerodynamics of WIGE craft with hydrofoil and WIGE craft only with fuselage of seaplane were implemented in Fluent for the longitudinal static stability, cruise performance and climb performance, respectively. The results show that the lift-to-drag of the WIGE craft with hydrofoil increases by 8.4% comparing with the WIGE craft with fuselage of seaplane, the longitudinal static stability margin of the WIGE craft with hydrofoil is smaller than the WIGE craft with fuselage of seaplane. The endurance and the climb performance of the WIGE craft with hydrofoil are better than the WIGE craft with fuselage of seaplane.d) Analysis of the lateral stability of the two craft sailing on the water was carried out in the CATIA software. The results indicate that the lateral stability of the WIGE craft with hydrofoil is weaker than the WIGE craft with fuselage of seaplane, but it is enough to meet the design requirements.e) The scaled models of both the WIGE craft with hydrofoil and the WIGE craft with fuselage of seaplane were made, and water skiing test of two models were also implemented. The results show that the drag of the WIGE craft with hydrofoil when skiing on the water is less than the WIGE craft with fuselage of seaplane. The experimental phenomena indicate that the WIGE craft with hydrofoil has a weaker ability to suppress the spray of water.