漂浮运动对风力机气动特性的影响分析

Effect of floating foundation motion on the aerodynamic characteristics of the floating offshore wind turbine

海上浮式风机为蕴藏丰富的深海风能开发提供了有效的解决方案,浮式基础存在的大幅度纵荡、纵摇和艏摇运动可以改变风轮与流场间的相互作用,从而影响风力机的气动特性。基于叶素-动量理论及其修正方法,以NREL 5MW风力机为研究对象,考虑浮式基础运动对叶片不同径向位置处相对入流风速的影响,提出了风载荷的计算模型,通过编程计算获得了叶轮转矩和风力机功率,并比较了不同运动形式对风力机功率波动的影响。结果表明,纵摇对其功率特性影响最大,这为海上浮式风机的优化设计提供理论依据与数据基础。

Floating offshore wind turbines are capable of exploiting the abundant deepwater wind resource. Because of the existing large motion of the floating platform, such as the yaw, the pitch and the surge motion, the interaction between the wind flow and the wind turbine blade will be changed, which will effect its aerodynamic characteristics. Considering the changed wind inflow velocity at different radial position along the span direction of the blade induced by the floating foundation motion, the aerodynamic load is calculated based on the blade-momentum theory and its various modified formulas. Taking the NREL 5MW sample offshore floating wind turbine as an example, the torque and power results are compared under different floating foundation motions. The analysis results show that the pitch motion has the most great effect on the power fluctuation, and are helpful to optimize floating offshore wind turbine design.