Numerical study of an aeroelastic energy harvester with operational wind envelope expanded by shape-memory elements and dynamic stall

Abstract A numerical study on the wind envelope enhancement of a pitch-and-plunge airfoil energy harvester by exploiting the cooperative effects of superelastic shape-memory alloy hysteresis and nonlinear aerodynamics related to dynamic stall is presented. Electromechanical coupling is considered in the airfoil plunge degree of freedom. Shape-memory behavior is considered in the pitch degree of freedom. Nonlinear aerodynamics to capture dynamic stall effects is represented by the Beddoes-Leishman model. The electrical power is evaluated for model parameters from the literature for comparison purposes. Numerical predictions reveal favorable scenarios for wind energy harvesting with stable post-flutter oscillation over a relatively wide range of airflow speeds. The results depict the attractiveness of combined structural and aerodynamic nonlinear effects, predicting bounded oscillations at higher post-flutter speeds when compared with cases for isolated structural or aerodynamic nonlinear effects. The amplitudes of oscillation are conveniently controlled by properly pre-loading the shape-memory elements. The operational envelope is attractive to concept novel wind energy harvesting devices.