关键词: 二维翼型, 代数网格, 非定常流动, 尾涡脱落

Abstract: The wake vortex shedding flow mechanism of airfoils at different Reynolds numbers (Re =5 ×10⁴ ，1 ×
10⁵ ，2 ×10⁵ ，5 ×10⁵ ，respectively) was analyzed in this paper，by generating algebraic meshes with Hermite in-
terpolation function． The results show that，when periodic flow occurs，Strouhal number increases with the increase
of Re at the same angle of attack as the fluid viscosity decreases; and that，the variation of lift coefficient of airfoil
is consistent with that of wake vortex shedding． The peak lift coefficient appears just after the tail edge counter-
clockwise vortex sheds，while the valley lift coefficient appears when the tail edge counterclockwise vortex reaches
the maximum size． When the airfoil enters the periodic flow state，the development law of wake vortex shedding is
2S (Single) mode first，then 2P (Pair) mode，chaotic state，and finally quasi-periodic flow state，as the angle of
attack increases． The investigation into the aerodynamic characteristics and wake vortex shedding mechanism pro-
vides a basis for the design of flow control methods．

Key words: two-dimension airfoil, algebraic meshes, unsteady flow, wake vortex shedding