Nonlinearly enhanced vortex induced vibrations for energy harvesting

In order to enhance the performance of an energy converter based on a vortex induced vibration (VIV) system, a model of nonlinear springs, the so-called hardening springs, is applied to widen the resonance range. A nonlinear spring is introduced by utilizing cantilever beams with additional plates to harden the structure partially. An experimental investigation is carried out to analyze the potential of hardening stiffness spring in widening the resonance range. A fluid-structure interaction (FSI) simulation is performed to validate the experimental results. A comparison to the experimental results from a similar system that utilized linear springs shows the potential of hardening springs in widening the resonance range of VIV energy converters.