Workflow- Based Shape Optimization of Airfoils and Blades using Chained Bezier Curves

Igor Pehnec, Damir Vučina, Željan Lozina (University of Split)

This paper presents an approach of generating object geometries by optimization of shape variables, applicable to 2D and 3D cases. Piecewise curves are employed and continuity at joints is ensured by adding extra points. This approach is applied to airfoils for wind turbine blades. Corresponding CFD simulation results and experimental wind tunnel values generally agree in shape, but the respective lift and drag coefficients differ somewhat. The difference in values can be attributed to the complexity of numerical flow simulations and corresponding assumptions as well as the fact that limited computer resources and CPU time are available for the finite element model. On the other hand, experimental graphs are also obtained by experiments where the conditions can not be controlled fully. Anyway, the degree of agreement and the evolution of shape from the random initial to the NACA- similar final shapes make the shape optimization process as proposed here successful.