عباس دشتی منش

In this thesis, we studied the flow of fluid around the semi-submersible hydrofoil. In recent years, semi-submersible hydrofoils have been known for its high efficiency and high lift-to-drag ratio. In this thesis, we first studied to verify the Harwood hydrofoil and compared the results with the simulation. Then we chose the Wild section for simulation, We simulated wild hydrofoil at different angles and for a different cavitation number. According to the results, the formation of the cavitation bubbles and the formation of aeration around the foil walled with the conventional sections in the semi-submersible hydrofoils are different. And this is due to the special geometric shape of the super-cavitation that has a geometric shape with a specific forehead. Certain sections of super-cavitation hydrofoils, in the low cavitation number, cause the water phase change to water saturated vapour, which results in a relative decrease in drag and an appreciable increase in lift. According to the results obtained in this simulation, the Wild cross-section with the increase in the number of cavitation, cause in high ratio lift to drag, and this process continues until it enters a completely soaked phase around the foil, which, with enters to this phase Because of increasing the level of wetted, the ratio of lift to drag coefficients is also reduced, so the wild section is recommended for designing a variety of semi-submersible hydrofoils as well as the design of super-cavitation.