水翼空化流场的调控和优化研究

In order to suppress the formation and development of cavitation in the flow field around the hydrofoil, this paper establishes a new hydrofoil with its profile optimized by comparing and analyzing the performance of three classical hydrofoils, NACA0009, NACA0012 and Clark Y under different working conditions. Then, several fluid control structures are uniformly arranged on the new hydrofoil, and optimized rapidly by generalized pattern search algorithm to realize general and local control of cavitation in the flow field. The results show that the new hydrofoil has a suction surface whose bulge height is between those of the NACA0012 and Clark hydrofoils, and its maximum bulge position is backward. The new hydrofoil shows improved cavitation performance(cavitation shedding suppressed)and hydrodynamic performance(backflow development suppressed), with its lift-drag ratio up by as high as 48.8%. The multiple control structures evenly arranged on the suction surface of the new hydrofoil can continuously suppress the backflow and improve the pressure distribution. They are accurately and rapidly optimized with an optimization algorithm. As a result, the performance of the optimized hydrofoil is further improved, with the lift-drag ratio further up by 4.8%-13.6%, and the thickness and length of cavitation reduced. Therefore, optimizing the profile and adding continuous flow control structures can realize the overall and local control of the cavitation flow field, providing an effective way to improve the cavitation and hydrodynamic performance of the hydrofoil.