本研究先对风力机S809翼型处于3种不同程度动态失速下的非定常流场进行CFD（计算流体动力学）数值模拟，得到了翼型在振荡周期内升阻力系数随攻角的变化曲线，然后采用DMD(动力模态分解）方法对非定常流场进行模态分析，从中得到了非定常流场变化过程的主要模态和相应的频率以及能量等信息。通过对前6阶主要模态所包含的流场信息进行对比分析，DMD方法成功捕捉到了复杂流场中不同尺度的流动结构，直观地显示了不同程度动态失速非定常流场之间的差别。

At first,CFD numerical simulation is carried out on the unsteady flow field around S809 airfoil under three different degrees of dynamic stall,and the variation curves of the lift and drag coefficients with the angle of attack are obtained in the airfoil’s oscillating period.Then the unsteady flow field can be analyzed with the dynamic mode decomposition (DMD) method,and the primary modes of the unsteady flow field and their corresponding frequencies and energy are obtained.By comparing the flow field information contained in the first six order modes,the DMD method successfully captures the flow structures at different scales in the complex flow field,and visually shows the differences between the unsteady flow fields under different degrees of dynamic stall

TK83

国家自然科学基金资助项目(51506123)