  In this article the energy transfer between a flow and a fluttering
piezoelectric plate is investigated. In particular, the benefits of the use of
a Synchronized Switch Harvesting on Inductor (SSHI) circuit are studied. Both
wind tunnel experiments and numerical simulations are conducted in order to
analyse the influence of the switching process on the dynamics and the
efficiency of the system. Numerical simulations consist of a weakly non-linear
model of a plate in axial flow equipped with a single pair of piezoelectric
patches, discretized using a Galerkin method where basis functions are the
modes of the plate in vacuum. The discretized model is then integrated in time.
The results presented in this paper show that a significant improvement of the
harvested energy can be obtained using SSHI circuits compared to basic
resistive circuits. It is also shown that for strongly coupled systems, the
switching process inherent to he SSHI circuit has a significant impact on the
dynamics of the flag, which tends to decrease the relative efficiency gain.
