弹性振动对翼型气动特性影响的数值模拟

Numerical simulation of elastic vibration on the airfoil aerodynamic characteristics

通过求解雷诺平均非定常Navier-Stokes方程,采用数值模拟方法计算了俯仰和沉浮振动对NACA0012翼型平均气动特性的影响。结果表明:对于俯仰运动而言,在迎角α≤13°时的升力和力矩曲线的线性段部分,振幅角的变化对动态平均升力系数和动态平均力矩系数的影响不明显,与静态时的情况基本一致;当迎角α≥14°时,翼型振动的平均升力系数和动态平均力矩系数小于静态时的情况。同一迎角条件下的俯仰振动频率越高时,其动态的平均升力系数和动态平均力矩系数越大,频率较高时的失速迎角相对于频率较低时的情况有所推迟,但相对于静态的失速迎角而言,不同频率下的动态失速迎角均提前。对于沉浮运动而言,动态平均升力系数随振幅和频率的增加而减小,动态失速迎角随振幅和频率的增大而提前。

Based on the Reynolds-Averaged Navier-Stokes equations,the airfoil aerodynamic characteristics under simple pitching are calculated numerically.The following concluions can be drawn from the calculated results: for pitching motion,at the lift and moment curve linear part of the angle of attack α≤13°,the change of amplitude angle to the dynamic average lift coefficient and dynamic average moment coefficient is not obvious,consistent with the static situation.While for the angle of attack α≥14°,the airfoil vibration average lift coefficient and the dynamic average moment coefficient are less than those of the static case.The higher the pitching vibration frequency of the same angle of attack,the greater the dynamic average lift coefficient and dynamic average moment coefficient.The high frequency stall angle of attack relative to the lower frequency has been postponed,but compared with the static stall angle of attack,dynamic stall angle of attack appears in advance.For plunging motion,the dynamic average lift coefficient decreases with the amplitude and the frequency increases and the dynamic stall angle of attack appears in advance with amplitude and frequency increases.