基于旋转杆的低雷诺数SD7003翼型流动控制研究

Flow Control on SD7003 Airfoil with Rotating Rod at Low Reynolds Number

为了研究翼型边界层内旋转杆对SD7003翼型的尾涡模式和气动特性的影响,本文基于高精度的谱单元方法,对α=4度及Re=5000下SD7003翼型进行直接数值模拟。通过改变旋转杆在边界层内的位置和转速比,发现SD7003翼型的4种尾涡脱落模式,结合对SD7003翼型升力系数的频谱分析,详细统计了旋转杆不同位置和转速比下的翼型尾涡模式,揭示了旋转杆能推迟甚至抑制边界层流动分离以及翼型尾涡模式随旋转杆的变化规律;根据对SD7003翼型气动特性的量化分析,发现平均升力系数最大可提高114%,平均阻力系数最大增加88%。增加转速比后,平均升力系数最大提升44%,升阻比提升幅值为56%。旋转杆对SD7003翼型有较好的控制效果,为低雷诺数下翼型的边界层控制提供方法和思路。

In order to investigate the effect of rotating rod in the boundary layer of the airfoil on the wake-vortex pattern and aerodynamics of the SD7003 airfoil,we performed direct numerical simulations of flow over SD7003 airfoil with angle of attack equals to 4 deg and Reynolds number equals to 5000 based on high-precision spectral element method.Four kinds of wake shedding modes of SD7003 airfoil are found by changing the position and speed ratio of the rotating rod in the boundary layer.Combined with the spectrum analysis of lift coefficient of SD7003 airfoil,the wake-vortex patterns of the airfoil at different positions and rotating speed ratios of the rotating rod are recorded in detail,which reveals that rotating rod can delay or even suppress flow separation of boundary layer and how wake-vortex patterns of airfoil vary with the rotating rod.According to the quantitative analysis of aerodynamic characteristics of SD7003 airfoil,it is found that the maximum mean lift coefficient can be increased by 114%,and the maximum mean drag coefficient can be increased by 88%.With increasing speed ratio,the maximum mean lift coefficient and lift-drag ratio can be increased by 44%and 56%,respectively.The rotating rod has a good control effect on the SD7003 airfoil,which provides a method and idea for the boundary-layer control of the airfoil at low Reynolds number.