Dynamic shape optimization of a vertical-axis wind turbine via blade morphing technique

The objective of this study is to introduce a new design of a Vertical Axis Wind Turbine (VAWT) that dynamically morphs its blades as a function of azimuthal angle and Tip Speed Ratio (TSR). Wing morphing constitutes the next generation shape-changing wing in aerospace industries. An optimization technique based on a Computational Fluid Dynamics (CFD), a Free-Form Deformation (FFD) algorithm in conjunction with mesh morpher coupled with various optimization methods that uses a Bernstein polynomial-based morphing scheme is adopted. The performance of the morphed-blade rotor is assessed against that of the fixed-blade. Validation results that demonstrate the attainment of this approach are presented. This methodology, which is applicable to any blade profile, led to substantial improvements in the delivered power output of the turbine when applied to a three-bladed rotor with NACA 0021 airfoil. A flap-like deflection of the trailing edge towards the incoming wind on both the upwind and downwind side of the turbine is observed in the optimized morphed shapes. (C) 2020 Elsevier Ltd. All rights reserved.