Research on Topology Transformation Method of Wind Turbine Airfoil

To expand the airfoil database, this paper proposes a new wind turbine airfoil based on topology theory. Firstly, the precise meaning of wind turbine airfoil characteristics and airfoil topology invariants are clarified. Secondly, the nonlinear mapping function of the high-order rotating surface is applied. Based on above, the non-linear mapping of the unchanged airfoil topology structure is realized. Finally, the topological transformation of the airfoil based on the commonly used airfoil S809 for wind turbines is performed, and new airfoils of different shapes are obtained by using different transformation parameters. The XFOIL software is used to study the aerodynamic characteristics of the original airfoil and the newly generated airfoil. The result shows that the airfoil obtained after the transformation may have a good performance or a poor performance simultaneously. The airfoil obtained having a good performance can be added to the airfoil database, whereas the one with poor performance can be optimized later to provide a basic airfoil for the optimal design of airfoil. This article provides a new method for wind turbine airfoil transformation, which broadens the ideas for blade airfoil design and optimization.