Computational study on aerodynamically coupled piezoelectric harvesters

In this work, the authors present a two-dimensional computational model for predicting the aeroelastic response as well as the output power of vertically arranged harvesters by taking into account all aerodynamic interactions. The piezo-aeroelastic framework consists of the following: (1) an aerodynamic model based on the unsteady vortex-lattice method to compute the aerodynamic forces; (2) a discrete parameter model for each harvester with 3 degrees of freedom (plunge motion, pitch motion, and the voltage generated by the piezoelectric effect); (3) an inter-model connection to exchange information between models at each time step; and (4) a numerical scheme based on the Hamming’s fourth-order predictor–corrector method to integrate all the governing equations in the time domain. The results obtained allow us to infer new insights into the flutter onset as well as the post-critical behavior of harvester arrangements. An interesting finding is that the flutter speed is significantly decreased as the distance between the harvesters is reduced. The results suggest the strong possibility of effective energy extraction at low flow speeds using properly distributed harvester arrangements. However, in post-critical conditions, the output power is significantly enhanced as the free-stream speed is increased.