Fluid-solid-electric lock-in of energy-harvesting piezoelectric flags

TL;DR

This paper investigates how inductive circuits influence the dynamics and energy harvesting efficiency of piezoelectric flags in steady flows, revealing destabilization and frequency lock-in effects that enhance energy extraction.

Contribution

It introduces a numerical study of fluid-solid-electric interactions, demonstrating how circuit optimization can improve flow energy harvester performance.

Findings

Inductive circuits destabilize the system, enabling energy harvesting at lower flow velocities.

Frequency lock-in between the flag and circuit significantly boosts harvesting efficiency.

Circuit optimization can lead to promising improvements in flow energy harvesting performance.

Abstract

The spontaneous flapping of a flag in a steady flow can be used to power an output circuit using piezoelectric elements positioned at its surface. Here, we study numerically the effect of inductive circuits on the dynamics of this fluid-solid-electric system and on its energy harvesting efficiency. In particular, a destabilization of the system is identified leading to energy harvesting at lower flow velocities. Also, a frequency lock-in between the flag and the circuit is shown to significantly enhance the system's harvesting efficiency. These results suggest promising efficiency enhancements of such flow energy harvesters through the output circuit optimization.