基于流固耦合的柔性翼型动态失速特性研究

Study on Dynamic Stall Characteristics of the Flexible Airfoil Based on Fluid-structure Interaction

为了研究柔性翼型在动态失速下的气动性能及其优势,从流动控制的角度,采用流固耦合数值模拟方法研究了具有被动大变形能力的柔性翼型动态失速特性并与传统的刚性翼型进行了比较.首先,对柔性翼型在不同减缩频率下的气动特性进行了研究,得到了减缩频率对柔性翼型气动特性的影响规律,同时定量比较了刚性翼型和柔性翼型的升阻力系数随攻角、减缩频率的变化规律.其次,从俯仰震荡翼型的涡量场、流线以及结构响应等角度揭示了柔性翼型在动态失速现象中依旧具有良好气动特性的关键物理机制.研究结果表明,在高减缩频率下,柔性翼型具有低阻力的特征,气动性能显著优于刚性;柔性翼型的被动变形可以抑制翼型表面涡旋的生成从而优化气动特性.

To study the aerodynamic performance of the flexible airfoil under dynamic stall,from the perspective of flow control,the dynamic stall characteristics of flexible airfoil with passive large deformation capability were studied by the fluid-structure interaction numerical simulation method and compared with the traditional rigid airfoil. Firstly,the aerodynamic characteristics of the flexible airfoil in different reduced frequencies were studied. The influence of reduced frequency on the aerodynamic characteristics of the flexible airfoil was obtained. Quantitative comparisons were made on the variation of the lift-drag coefficient of rigid airfoil and flexible airfoil with attack angle and reduced frequency. Secondly,from the perspective of the vorticity field,streamline and structural response of the pitching oscillation airfoil,the key physical mechanism that the flexible airfoil still has good aerodynamic characteristics in the dynamic stall phenomenon was revealed. The results show that at high reduced frequency,the flexible airfoil has the characteristics of low drag,and the aerodynamic performance of the flexible airfoil is significantly better than that of the rigid airfoil. The passive deformation of the flexible airfoil can suppress the generation of vortex on the airfoil surface and optimize the aerodynamic characteristics.