Modelling of Cantilever-Based Flow Energy Harvesters Featuring C-Shaped Vibration Inducers: The Role of the Fluid/Beam Interaction

Abstract

Flow Energy Harvesters (FEHs), equipped with piezoelectric active layers, are designed to extract energy from non-pulsating flows. FEHs featuring cantilevers with tip-mounted Vibration Inducers (VIs) are designed to develop a galloping motion. In this paper, we present the modelling of a recently introduced VI shape, featuring semitubular-shaped winglets, which do not produce a wake interacting with the cantilever. Such peculiarity allows (i) to exploit the contribution of the wake to the formation of the lift, therefore opening to a more compact design; (ii) its performance to be analyzed by means of simple two-dimensional Computational Fluid Dynamics (CFD) simulations. By comparison with experimental data, we show that the minimal framework for the modelling of such new class of VIs needs to account for both the direct action of the fluid onto the cantilever and the drag on the VI, which are usually negligible for other VI shapes.