大型后掠自适应风力机叶片的气动扭角设计优化

The twist angle design and optimization of large sweep twist blade

针对大型后掠式自适应叶片(STB)中显著的气动/结构耦合现象,利用优化方法探讨了直叶片转化为后掠式自适应叶片后的气动扭角补偿优化,STB叶片没有不改变原直叶片的输出功率和结构强度。优化算法采用遗传算法,以功率为约束条件,扭角分布为优化变量,优化目标为叶片根部应力最小。建立了叶片的气动模型和六自由度铁摩辛科悬臂梁结构模型,叶片的气动特性分析采用了基于动量叶素理论的数值算法,结构特性分析采用有限元法,优化算法采用遗传算法。最后在额定风速条件下,完成了2.0MW叶片的气动扭角的补偿设计优化。分析结果表明,STB叶片通过扭角补偿后,可满足功率输出的要求,并大幅降低叶片的轴向推力。

aimed to the significant aero-structure coupling of the large sweep twist adaptive blade（STB）,the Multidisciplinary optimization（MDO） was used to compensation of twist angle distribution of the STB whitch transformed from modification of a traditional blade aero-shape directly,The power and the stiffness of structure would not changed.The blade aerodynamics model based blade-element momentum theory and the FEM structure model based Timoshenko beam was set up,the Genetic algorithm（GA） was applied during the optimization,the object was the blade weight,subjected to the out power of the blade,the chord of sections and the thick of the skin of the blade was set to variables.A analysis based 2.0MW STB blade shown that the axial force decreased sharply with the satisfied power out requirement.