Wind Turbine Blade

In MAE 4272, our team designed and optimized a small wind turbine blade  for low-wind conditions, aiming to maximize power output under a  Weibull-distributed wind profile with a mean speed of 4.59 m/s. The  objective was to achieve a target operating point of 1739 RPM, 3.31 N·cm  torque per blade (scaled for three blades), and 6.02 W power, while  adhering to structural constraints like a maximum stress of 36.67 MPa.  We simplified aerodynamics to steady 2D flow at Re ≈ 50,000, ignoring  minor 3D effects and friction for efficient evaluation, and selected the  NACA 4412 airfoil for its superior lift-to-drag ratio at low Reynolds  numbers compared to alternatives like S1223 and S822. 

The design process featured a parallel workflow: a Python-based  differential evolution optimizer refined parameters such as 10 pitch  angles, root chord, and RPM, discretizing the blade into 10 segments for  aerodynamic and structural analysis using blade element theory and beam  bending. Concurrently, CAD modeling in Fusion 360 parameterized  geometry for manufacturability, incorporating adjustments like  truncating the airfoil trailing edge to strengthen the hub connection  without major aerodynamic loss. Key iterations included  post-optimization smoothing of pitch angles for monotonic distributions  and penalty functions to enforce constraints, linking numerical results  directly to a 3D-printable model. 

My specific contributions included developing the engineering model used  for the optimizer and the differential evolution optimizer to  iteratively maximize expected power while respecting constraints. I also  contributed to wind tunnel testing, data collection, and analysis,  where I identified opportunities for enhancement, such as increasing  population size for better exploration, tuning hyperparameters to reduce  variability, and integrating experimental Cl/Cd data for more accurate  modeling.