An efficient and automated method to generate complex blade geometries for numerical analysis

摘要

This paper presents an efficient and automated algorithm for the generation of straight and curved blades, as used in horizontal- and vertical-axis wind turbines. A single B-spline surface with both structural and aerodynamic zones is constructed, based on Non-Uniform B-splines Functions. The overall process of the approximation of both 2D blade airfoils and 3D blade surfaces is presented. The main algorithm is designed to construct a detailed B-spline surface, minimizing the segmentation data of the blade and the number of control points needed. A comparison between uniform and non-uniform B-splines blades is conducted using strain energy analysis. Additionally, the Double Reflection Method is implemented as a Rotation Minimizing Frame for a robust transformation of a 3D straight blade into a curved blade, following an arbitrary 3D pole curve. The final output of the main algorithm is a low-resolution control mesh that can regenerate a high-resolution 3D curved NURBS blade. The novel method is designed as a pre-step for numerical analysis, such as classical Finite Element Method and Isogeometric Analysis.