Harvesting energy via fluttering piezoelectric beams in viscous flow

This work explores the idea of harvesting energy from ambient flows using flexible piezoelectric beams. Beams lose their stability and flutter above a critical length or flow speed or below a critical stiffness. During flutter, beams oscillate in increasing amplitude until they enter a self-sustained limit cycle oscillation, which could be exploited to harvest energy. The objectives of this study are to: (i) identify the flutter boundary of a flexible beam in viscous flow; (ii) explore the energy harvesting potential; and (iii) identify critical non-dimensional parameters and parametric relations that govern the response and stability of thin composite beams vibrating in a viscous fluid. Two-dimensional Navier-Stokes equations are solved with a nonlinear beam model coupled with a linear piezoelectric material constitutive model. The harvested energy potential for various solid/fluid combinations is investigated by varying the critical non-dimensional parameters, which are defined in terms of beam length, density, thickness, and stiffness; fluid speed and density; and piezoelectric material properties.