基于强迫振动和自由振动的风力机翼型涡激振动数值研究

Numerical Study on Vortex-induced Vibration of Wind Turbine Airfoil via Prescribed Vibration and Free Vibration

基于动网格技术,分别采用强迫振动和自由振动方法对90°攻角下风力机翼型的涡激振动现象进行了数值研究。通过强迫振动计算方法,确定了Du96-W-180风力机翼型在不同振幅下的涡振区间,并比较了改变来流速度和改变结构刚度对涡振区间的影响;通过自由振动计算方法,获得了不同来流速度下的翼型涡振区间,对比了频率比r=0.93和r=1.11时不同结构阻尼对翼型振动响应的影响,分析了翼型涡振的发展和演化过程。结果表明:改变来流速度和改变结构刚度时不同频率比下的涡振区间基本一致;自由振动数值计算验证了强迫振动的涡振区间;不同频率比下6%结构阻尼比时翼型振动出现涡激振动和强迫振动2种形式。

Based on the dynamic mesh technique,the vortex-induced vibration of wind turbine airfoil at 90°angle of attack was numerically studied by using the prescribed vibration method and the free vibration method respectively.Through the prescribed vibration calculation method,the vortex-induced vibration range of Du96-W-180 wind turbine airfoil at different amplitudes was determined,and the effects of changing the incoming flow velocity and changing the structural stiffness on the vortex-induced vibration range were compared.Through the free vibration calculation method,the vortex-induced vibration range of the airfoil at different inflow speeds was obtained.The influence of different structural damping on the vibration response of the airfoil at the frequency ratio r=0.93 and r=1.11 was compared,and the development and evolution process of the vortex-induced vibration of the airfoil were analyzed.Results show that vortex-induced vibration range at different frequency ratios is basically the same while changing incoming flow velocity and changing the structural stiffness.The free vibration numerical simulation verifies the vortex-vibration range of the forced vibration.When 6%structural damping is applied at different frequency ratios,the vibration of the airfoil exhibits two forms:vortex-induced vibration and forced vibration.