A Novel Small-Scale Bladeless Wind Turbine Using Vortex-Induced Vibration and a Discrete Resonance-Shifting Module

The bladeless wind turbine (BWT) using vortex-induced vibration is a new class of wind turbine that does not have traditional rotating blades and converts wind energy into vibration energy and into electrical energy based on vortex-shedding principles. Since conventional BWTs are only efficient for a small range of wind speeds near the structural resonant frequency, this study proposes a novel bladeless wind turbine that can tune the resonant frequency for a wider range of wind speeds to improve the effective power generation region. This study designed a discrete on–off resonance-shifting module based on a smart material with variable stiffness that can easily tune the structural frequency of the BWT to two different wind speed classes to enhance power generation efficiency. Experiments were conducted to confirm that the designed BWT can shift the resonant frequency of the structure by 60% and can operate in the ranges of light breezes and gentle breezes. Furthermore, a series of experiments present the power generation effectiveness of the proposed BWT under these different wind speed conditions.