复合运动下风力机翼型动态失速特性研究

STUDY ON DYNAMIC STALL CHARACRERISTICS OF WIND TURBINE AIRFOIL UNDER COMPOUND MOTION

采用带γ-Reθ转捩修正的SST k-ω湍流模型和动网格技术,以S809翼型为研究对象,探讨复合(俯仰+前后横荡)运动下的动态失速特性。结果表明:横荡运动扩大了翼型升阻力系数迟滞环状;上仰阶段升力系数增加,阻力系数减小,增减幅度与横荡幅度成正比;降低了下俯阶段的升力系数。横荡运动通过改变翼型边界层流体动能,有效缩小翼型尾缘涡的拓扑结构,增强前缘涡的诱导效应,使得翼型上仰阶段失速程度减弱。

Wind turbine normally occurs dynamic stall due to wind shear,yaw,pitch and other factors.In the six-dimensional motions,surge motion has a significant impact on the aerodynamic characteristics of floating wind turbine,and the influence law of its dynamic stall characteristics are worth discussing.The SST k-ωturbulence model with theγ-Reθtransition model and dynamic grid technique are used to study dynamic stall characteristics of S809 airfoil under the influence of compound motion(surge+pitch).The results show that,surge motion enlarges the hysteresis loop of the lift and drag coefficient.The lift coefficient increases and drag coefficient decreases in the pitching up stage,and the fluctuating amplitude is proportional to the amplitude of surge.The lift coefficients decrease in the pitching down stage.By changing energy of the airfoil boundary layer,surge effectively reduces the topology of the trailing edge vortex,enhances the induction effect of the leading-edge vortex,and weakens the dynamic stall degree of the airfoil in the pitching up stage.This study reveals the dynamic stall characteristics of airfoil under surge motion,which is important to accurately understand and evaluate the aerodynamic performance of floating wind turbine.