考虑转捩的风力机翼型动态失速数值模拟

以风力机专用翼型的动态失速为对象,采用一种基于流场当地变量的Gamma-Theta转捩模型配合SSTk-ω湍流模型进行数值模拟,研究转捩对动态失速性能的影响和动态失速下的转捩规律。结果表明,使用考虑转捩效应,能够使动态失速过程中上仰段大迎角状态下失速和下俯段气流再附的模拟得到改善。在动态失速上仰段,上表面转捩由后缘分离泡向前缘分离泡的转变过程较快,导致转捩点迅速前移;而在下俯段,前缘分离泡向后缘分离泡的转变过程中经过了自然转捩和再层流化的过渡,因此转捩点的移动较上仰段平滑。

NUMERICAL SIMULATION OF WIND TURBINE AIRFOIL DYNAMIC STALL WITH TRANSITION MODELING

A numerical simulation using a local variable based Gamma-Theta transition model incorporating with SST k-ω turbulence model on the dynamic stall of wind turbine aerofoil has been made to investigate the influence of transition on dynamic stall and the transition rule of dynamic stall.It is shown that an inclusion of the transition effects can improve the simulation of stall at high angle of attack during upstroke and flow reattachment during downstroke in dynamic condition.During the upstroke,the separated bubble moves quickly from the trailing to the leading edge of the airfoil,resulting in a fast forward of transition onset location.During the downstroke,the relaminarization and natural transition bridge this transformation process,leading to a more gentle movement of transition onset location compared to the upstroke.