不同涡流发生器参数对潮流能水轮机翼型水动力学特性影响研究

INFLUENCE OF DIFFERENT VORTEX GENERATOR PARAMETERS ON HYDRODYNAMIC CHARACTERISTICS OF TIDAL CURRENT TURBINE HYDROFOIL

将涡流发生器(VGs)流动控制理论引入到水轮机叶片设计领域,开展涡流发生器对潮流能水轮机叶片流动分离效应的抑制机理及水动力学特性研究。以NACA4418翼型为研究对象,分别建立基础翼型段和带VGs翼型段的潮流能水轮机翼型三维模型,应用CFD方法研究不同VGs排布方式、间距、高度以及长度参数对翼型段水动力性能的影响。结果表明:翼型段上安装VGs能有效减缓流动分离,合理的VGs排布方式可有效提高翼型的最大升力系数,正向排布优于反向排布,VGs间距为25 mm、高度为5 mm、长度为17 mm时对翼型段改善效果最佳,各组带VGs翼型最大阻力系数都增大约5%,翼型整体性能上升。利用水槽试验的方法验证仿真模型的准确性。此外,通过对翼型段进行二维流场分布以及VGs背流侧进行静压分布研究,进一步揭示VGs的作用机理。

In this paper,the flow control theory of vortex generators(VGs)is introduced into the field of turbine blade design,and the inhibition mechanism and hydrodynamic characteristics of vortex generators(VGs)on flow separation effect of tidal current turbine hydrofoil are studied. NACA4418 hydrofoil is taken as the research object,the three-dimensional models with VGs and without VGs are established respectively. The effects of different parameters of VGs,such as VG arrangement,spacing,height and length,on the hydrodynamic performance of NACA4418 hydrofoil are studied by CFD method. The results show that VGs can effectively suppress the flow separation and improve the maximum lift coefficient of hydrofoil. The performance of forward VG arrangement is better than that of the reverse arrangement. The best improvement effect is obtained when the distance between VGs is 25 mm,the height is 5 mm and the length is 17 mm. Although the maximum drag coefficient of each hydrofoil with VGs is increased by about 5%,the overall performance of hydrofoil is increased. The accuracy of the simulation results is verified by flume tests. In addition,two-dimensional flow field distribution around hydrofoil section and static pressure distribution on VG’s backflow side are studied to further reveal the mechanism of VGs.