Electro-hydrodynamic synchronization of piezoelectric flags

TL;DR

This paper explores how electrodynamic coupling, especially through resonant circuits, can synchronize piezoelectric flags in flow, significantly improving energy harvesting efficiency by dominating hydrodynamic interactions beyond a certain distance.

Contribution

It demonstrates that electrodynamic coupling can surpass hydrodynamic effects in flag synchronization and energy harvesting, and shows how resonant circuits can enhance this coupling.

Findings

Electrodynamic coupling dominates hydrodynamic effects beyond a critical distance.

Synchronization through electrodynamic coupling improves energy harvesting efficiency.

Resonant circuits further strengthen electrodynamic coupling and energy output.

Abstract

Hydrodynamic coupling of flexible flags in axial flows may profoundly influence their flapping dynamics, in particular driving their synchronization. This work investigates the effect of such coupling on the harvesting efficiency of coupled piezoelectric flags, that convert their periodic deformation into an electrical current. Considering two flags connected to a single output circuit, we investigate using numerical simulations the relative importance of hydrodynamic coupling to electrodynamic coupling of the flags through the output circuit due to the inverse piezoelectric effect. It is shown that electrodynamic coupling is dominant beyond a critical distance, and induces a synchronization of the flags' motion resulting in enhanced energy harvesting performance. We further show that this electrodynamic coupling can be strengthened using resonant harvesting circuits.