基于节点位移法的变耦合区域风力机叶片弯扭耦合效应分析

Analyses on Bend-twist Coupling Characteristic of Wind Turbine Blade with Varied Coupling Region Based on the Nodal Displacement Method

弯扭耦合风力机叶片可以有效降低叶片极限载荷,但会增加叶片发生气弹不稳定的风险,耦合区域对叶片弯扭耦合性能有重要影响。基于节点位移给出了弯扭耦合系数及等效弯扭耦合系数的定义,将弯扭耦合系数视为叶片整体属性,可以考虑耦合区域对叶片弯扭耦合特性的影响。以NREL 5 MW风力机叶片作为基准模型,设计了变耦合区域弯扭耦合叶片,研究耦合区域、铺层角度和叶片材料对弯扭耦合叶片的变形及其等效弯扭耦合系数的影响。数值计算结果表明,全区域碳纤维叶片弯扭耦合效应最显著;而全区域玻璃纤维-碳纤维混合铺层叶片也可以获得较显著的弯扭耦合效应。

Bend-twist coupling blade has the ability to reduce the ultimate load but it faces the risk of aeroelastic instability.Coupling region has an important influence to bend-twist coupling characteristic.The bend-twist coupling coefficient and its equivalent coefficient are given based on the nodal displacement.This definition can study the effect of the coupling region to the bend-twist coupling of blade as it is a blade global property not only a section property.With the NREL 5 MW wind turbine blade as a benchmark model,a series bend-twist coupling parametric blades with varied coupling regions are designed to study the influence of coupling region,the ply orientation and the ply material to the bend-twist coupling characteristic.Numerical results show that carbon fiber blade with whole coupling region has the most notable bend-twist coupling characteristics and the glass fiber,carbon fiber mixed layer blades also has a remarkable bend-twist coupling characteristics.