Numerical Investigation of Flow-Induced Vibration of a Cantilever Beam for a Piezoelectric Energy Harvester

Flexible cantilever beams in channel flow loses its stability through a flutter mechanism at sufficiently high Reynolds number. This sustained transfer of flow work to cantilever beam oscillation could be extracted to generate electrical power, which may be utilized to power wireless sensors for structural health monitoring or supply additional power in unmanned or micro air vehicles. Such flexible beam system is known to exhibit some form of hysteresis, with super- and sub-critical velocities for onset of flutter, which may not be captured by current potential flow modeling. We present numerical simulation of a viscous, Navier-Stokes solver coupled to a cantilever beam, to capture this flutter velocity hysteresis. Numerical result under a linearly varying flow velocity shows an approximately 11% hysteresis, suggesting potential of present model for identifying more accurate boundaries of beam flutter. The prediction of cantilevered piezoelectric beam response under varying or unsteady flow velocities is necessary for reliable design of energy harvesting devices and warrants further experimental investigations.