流动控制组合对潮流能水轮机翼型水动力学的特性影响研究

INFLUENCE OF COMBINED FLOW CONTROL ON HYDRODYNAMIC CHARACTERISTICS OF TIDAL TURBINE HYDROFOIL

为全面提升潮流能水轮机叶片的水动力学性能,将格尼襟翼(GF)和涡流发生器(VGs)的附加件组合引入到潮流能水轮机领域,研究附加件组合对改善水轮机叶片水动力性能的作用机理。以NACA4418翼型为研究对象,分别建立加装格尼襟翼、涡流发生器和二者流动控制组合的水轮机翼型三维模型,应用数值模拟方法研究流动控制组合对水轮机叶片水动力性能的影响机理。结果表明:安装GF可有效提高翼型段的升力系数,但会降低翼型的失速角;安装VGs可抑制翼型段吸力面的流动分离、增大翼型段的失速角,但攻角越小水动力学性能改善效果越不明显;GF和VGs的流动控制组合则可将二者优势充分结合,在全面提高翼型段升力系数的同时,还可抑制翼型表面的流动分离、增大翼型的失速角,从而获得最佳的流动控制效果。

In order to improve the overall hydrodynamic characteristics of tidal turbine blades,this paper introduces the combined flow control method based on Gurney flap(GF)and Vortex generators(VGs)into the field of turbine blade design,and studies the mechanism of the combined flow control approach on the hydrodynamic characteristics of turbine blades.With NACA 4418 hydrofoil as the research object,the three-dimensional models of tidal turbine hydrofoils installed with GF,VGs and their combination are established respectively,and the influences of GF,VGs and their combination on the hydrodynamic performance of turbine blades are studied by numerical simulation method.The comparative research results indicate that the lift coefficient of the hydrofoil section can be effectively improved by installing GF,but the stall angle of the hydrofoil is reduced;the installation of VGs can suppress the flow separation on the suction surface of the hydrofoil section and increase the stall angle,but the improvement in the performance of the hydrofoil is not obvious as the angle of attack becomes small;the flow control combination of GF and VGs can combine their advantages,and it not only improves the lift coefficient of the hydrofoil section,but also suppresses the flow separation and increases the stall angle of the hydrofoil,thus achieving the best flow control effects.