Improved B-Spline Skinning Approach for Design of Hawt Blade Mold Surfaces

The intricate 3D design of wind turbine blades has caused unwanted problems for blade designers and blade mold manufacturers. For example the cord length variation and twisting of airfoils, change of the airfoil type and the blade pre-bend can introduce major geometric complications. A novel method is suggested to improve 3D modeling of the blade mold surfaces as well as the required parting lines during the design process of the wind turbine blade. In the proposed algorithm, the blade leading edge surface is trimmed by parting lines calculated based on the blade silhouette while keeping G1 continuity of resulting surfaces. The Minimum Variation Surface (MVS) and strain energy fairing criteria approve that blade mold surfaces obtained by the developed method have better fairness compared to the surface created by the well-established design method. All programs are written in MATLAB and the final surfaces are converted into the standard IGES file format which is importable into any commercial CAD/CAM system.