Energy harvesting using an aerodynamic blade element at resonant frequency with air excitation

In this research, we propose an energy harvesting structure with a flexible blade element vibrating at its first mode to maximize the power output of the piezoelectric material. For this purpose, a piezoelectric patch was attached on the blade element used in a small-scale wind turbine, and air load was applied with a suitable angle of attack in the stall zone. The aerodynamic load created by air excitation vibrates the blade element in its first natural frequency and maximizes the voltage output of the piezoelectric patch. The variation of power outputs with respect to electrical resistance, air speed, and extra mass is experimentally investigated for various cases. An analytical model is constituted using a single-mode blade element with piezoelectric patch dynamics, and the power outputs of the obtained model are compared with experimental results.