Linear and Nonlinear Modeling and Experiments of a Piezoaeroelastic Energy Harvester

In this paper a piezoaeroelastically coupled lumped-parameter model for energy harvesting due to flow excitation is presented. A two-dimensional airfoil having two degree of freedom, i.e. pitch and plunge, is investigated. Piezoelectric coupling is considered for the plunge degree of freedom. Therefore an additional electrical degree of freedom is added to the problem. A load resistance is considered in the electrical domain. The unsteady aerodynamic loads are obtained from a time domain lumped vortex model. Two case studies are presented here. First the interaction of piezoelectric energy harvesting and a linear aeroelastic typical section is investigated for a set of electrical load resistances. Time domain responses for pitch and plunge as well as for the electrical outputs (voltage, current and electrical power) are presented. The linear model predictions are compared against experimental results. Later a concentrated nonlinearity (free play) is added to the pitch degree of freedom and the typical section is used to investigate LCO for piezoelectric energy harvesting.