Piezoelectric coupling in energy-harvesting fluttering flexible plates : linear stability analysis and conversion efficiency

TL;DR

This study analyzes how piezoelectric materials can harvest energy from fluttering flexible plates in axial flow, using linear stability analysis to optimize conversion efficiency and understand the destabilization effects.

Contribution

It provides a fully-coupled linear model of fluid, solid, and electrical systems for energy harvesting, including stability analysis and efficiency optimization.

Findings

Piezoelectric coupling introduces damping and can destabilize negative energy waves.

Destabilized flutter modes maximize energy conversion efficiency.

Global analysis confirms destabilization effects in finite-length plates.

Abstract

This paper investigates the energy harvested from the flutter of a plate in an axial flow by making use of piezoelectric materials. The equations for fully-coupled linear dynamics of the fluid-solid and electrical systems are derived. The continuous limit is then considered, when the characteristic length of the plate's deformations is large compared to the piezoelectric patches' length. The linear stability analysis of the coupled system is addressed from both a local and global point of view. Piezoelectric energy harvesting adds rigidity and damping on the motion of the flexible plate, and destabilization by dissipation is observed for negative energy waves propagating in the medium. This result is confirmed in the global analysis of fluttering modes of a finite-length plate. It is finally observed that waves or modes destabilized by piezoelectric coupling maximize the energy conversion efficiency.