基于响应面方法的风力机叶片多目标优化设计研究

运用基于响应面方法的优化设计技术,于径向使用NPU-WA-风力机专用翼型族的某1.5MW水平轴风力机叶片的多目标、多约束优化设计研究中。风力机气动性能使用基于叶素-动量理论的风力机性能分析和设计软件PROPID51。设计变量为叶片径向外形参数,包括弦长和扭转角分布,但是相对厚度保持不变;设计目标为年发电量和功率系数的最大化;在多目标优化中,使用"统一目标函数"法将多个设计目标函数通过加权求和统一到一个目标函数中。为减小计算量,响应面模型使用不含二阶交叉项的二阶多项式模型;构建模型中试验点的选择满足D-优化准则。以某1.5MW变速变矩型风力机叶片为例,进行了优化设计研究。叶片径向使用西北工业大学翼型研究中心设计的NPU-WA-风力机专用翼型族,使用CFD计算的气动性能数据作为输入进行了设计,分析了目标函数的权值分配对设计结果的影响;使用风洞测量自由转捩的气动性能数据进行了设计并分析了表面光滑条件对气动性能的影响。

Multi-objective aerodynamic optimization design of wind turbine blade based on response surface methodology

Optimal technique based on Response Surface Methodology(RSM) is employed in a multi-objective optimization design of a 1.5MW horizontal-axis wind turbine(HAWT) blade with NPU-WA series airfoils for wind turbine application used along the span.The software of PROPID51 for the design and analysis of HAWT based on Blade Element Momentum(BEM) theory is used to predict the aerodynamic performance.The design variables are the blade shape parameters including chord and twist distributions along the span while relative thickness distributions are maintained.The objectives of the model are the maximums of Annual Energy Production(AEP) and power coefficient.A composite function called desirability function is built using the weighted sum of the individual objective function.The reduced quadratic polynomial without the second-order-cross items are used as RS model to reduce the computational cost and the set of design points is selected to satisfy D-optimality.The optimal design is performed on a 1.5 MW variable-pitch and variable-rpm wind turbine blade and the NPU-WA series airfoils developed in Northwestern Poly.Univ.for wind turbine application are used along the span.The calculated aerodynamic performance of airfoils is used as inputs in optimal design to analyze the effects of the weight factor of the individual objective function;experimental aerodynamic performance at free transition condition is used in design as well and the effects on aerodynamic performance of HAWT for clean and soiled surface conditions are analyzed.