Hydrodynamic piezoelectric energy harvesting with strong shedding vortices by metasurface and wake–excited

Metasurface can affect the transverse oscillation of single cylinder in water, and the vibration will be more complex when interference cylinder is introduced. To analyze the behavior of the cylinder with wrapped–metasurface under wake–excited and to find an optimal design for energy harvesting, a segmented parametric model considering wake–excited is proposed. The wake–excitation coefficient is introduced to obtain the hydrodynamic force, and the electro–mechanical coupling dynamic model of harvester is established by extended Hamilton's principle and Gauss' law, the analytical solutions of output voltage and vibration displacement are obtained by decoupling model. The actual output is derived from water channel experiment, which verifies the model accuracy. The results show that the application of metasurface cancels the cylindrical “Lock–in” interval. Compared to the ‘Isolated cylinder’ case, the output voltage is 17.63 V and amplified by 15.47 times when spacing ratio is 1.8 and metasurface is the semi–elliptical feature. The numerical simulation explains that the simultaneous application of metasurface and wake–excited induces stronger shedding vortices, which significantly enhances the energy harvesting. •A segmented parametric model considering wake-excited is proposed.•The analytical model is validated by the U-shaped water channel experiments.•The application of metasurface cancels the cylindrical “Lock-in” interval.•Metasurface and wake-excited can greatly enhance harvester performance.•Metasurface and wake-excited induces strong shedding vortices.