A numerical investigation on piezoelectric energy harvesting from Vortex-Induced Vibrations with one and two degrees of freedom

Abstract

This paper presents numerical investigations into the dynamics of a rigid cylinder, mounted on elastic supports fitted with piezoelectric harvesters and subjected to the Vortex-Induced Vibrations (VIV) phenomenon. Hydrodynamic loads are considered by wake-oscillators models, whereas linear constitutive equations are adopted aiming at coupling the solid and electric oscillators. The main objective is to highlight the influence of an additional structural degree of freedom (namely, in-line oscillations) on the dynamics of the fluid–solid-electric system.For a particular set of dimensionless parameters that define the harvester circuits, oscillation amplitudes, electric tension and harvested power are obtained for different reduced velocities. Among other findings, the simultaneous presence of in-line and cross-wise oscillations can be emphasized to lead to a marked increase in the maximum energy harvesting efficiency.In addition to this analysis, a sensitivity study with respect to the influence of the dimensionless quantities that characterize the piezoelectric harvesters is carried out. The study shows that the energy harvesting efficiency can be increased by up to 50% for a particular reduced velocity.