Three-Dimensional Modified Cross-Section Hydrofoil Design and Performance Study

To improve the hydrodynamic performance of hydrofoils, this study combines the shape characteristics of flat and elliptical wings, uses parabolic function to fit the leading and trailing edges of hydrofoils, introduces the cross-section coefficient λ to characterize the cross-sectional size of hydrofoils along the spreading direction, and designs five hydrofoils with different cross-sections. The motion of the hydrofoil is simulated using the finite element analysis software Fluent to obtain the hydrodynamic performance curve of the hydrofoil and analyze the effect of different end face sizes on the performance of the hydrofoil. The results show that compared with the flat wing, the peak drag of the variable section hydrofoil with λ = 0.5 is reduced by 9.3%, the pitching moment is reduced by 23.1%, and the average power is raised by 17.4%. If the appropriate reduction in the cross-section coefficient is too small, it will exacerbate the wing tip vortex shedding, the hydrofoil surface pressure will be too concentrated, and the hydrofoil motion stability will be reduced. The lift coefficient, drag coefficient, and pitching moment coefficient of the hydrofoil are positively correlated with the cross-section coefficient λ, and positively correlated with the motion frequency.