Bionic Hydrofoil Design And Performance Research Based On Sturgeon

Most hydrofoils of hydraulic machinery adopt NACA series airfoils,but NACA series airfoils are mostly applied in the air environment,which will also affect the performance of hydraulic machinery to a certain extent.Studies have found that the shape curve of sturgeon has better drag reduction effect.In this paper,the sturgeon is taken as the research object.The geometric characteristics of sturgeon are extracted by high-precision three-dimensional reverse scanning technology.The dimensionless point coordinate system is established according to the appearance curve of sturgeon.The lift and drag coefficients,tip vortices and pressure distribution of the bionic sturgeon hydrofoil are analyzed by numerical simulation.Meanwhile,by optimizing the leading edge of the hydrofoil,the fitted hydrofoil of sturgeon was optimized,numerical simulation and experimental study were conducted on the optimized bionic airfoil of sturgeon.The cavitation region of sturgeon bionic hydrofoil at different angles of attack and the cavitation development process in a single period were studied by means of high-speed photography.The main conclusions of this paper are as follows:(1)Before reaching the stall angle of attack,the lift coefficient of sturgeon bionic hydrofoil is greater than NACA0012 and NACA0015 hydrofoil;At the same Reynolds number,the stall angle of the sturgeon bionic hydrofoil is similar to that of NACA0012 airfoil,but smaller than that of NACA0015 hydrofoil;NACA0012 and NACA0015 hydrofoil are more likely to produce and diffuse tip vortices than sturgeon hydrofoil.(2)The lift coefficient and drag coefficient of the optimized hydrofoil have little change,the optimized hydrofoil can reduce the cavitation of hydrofoil leading edge to some extent.(3)The critical cavitation angle of hydrofoil is between 10 ° and 12 ° in the experiment.With the increase of the angle of attack,the leading edge cavitation area increases gradually,and cloud cavitation is more likely to occur between the maximum thickness of the hydrofoil and the trailing edge.