Aerodynamic Load Analysis and Fiber Orientation Optimization for Composite Blades

A new methodology of aerodynamic load analysis and fiber orientation optimization for wind turbine blades is presented in this study. The airflow velocities in the rotating plane of the wind turbine are computed utilizing the modified blade element momentum (BEM) theory. Newton's interpolation format is utilized to construct the prediction model of the pressure coefficient for the airfoil profile. The pressure coefficients are amended via an equivalence of calculated aerodynamic performance with the experimental data. Consequently, the detailed aerodynamic loads on the blade surface are provided with a relatively lower computational cost. Subsequently, the calculated distribution forces are applied to the wind turbine blade for structural analysis and optimization. The mathematical model of the fiber orientation optimization for composite blades is constructed with the artificial density as the design variable, the density boundary and summation as constraints, and the minimum structural compliance as optimization objective. The optimization results demonstrate that the blade stiffness and strength could be greatly enhanced via the optimization of fiber orientation. This study provides an approximate but efficient methodology for obtaining the aerodynamic loads and an effective technique of fiber orientation optimization for wind turbine blade design.