On the Optimal Piezoelectric Material Distribution in Energy Harvesting From a Nonlinear Beam Under Axial Flow

The recent literature of energy harvesting has shown growing interest in nonlinear aeroelastic systems for wind energy harvesting. Among other configurations, electrical power extraction from limit cycle oscillations of nonlinear beams and plates combined with a transduction mechanism in axial flow (inspired by flapping flags) have been pointed out as an alternative to traditional horizontal axis wind turbines if implemented on a large scale. Although the literature presents several works on the modeling and experimental verification of cantilevered plates in axial flow using piezoelectric transduction mechanism, the investigation of piezoelectric material distribution along the body length for proper electrode configuration to avoid cancelation of electrical outputs has not been covered. To address this problem, in this work, a fluid-structure interaction model that couples nonlinear beam equation with a lumped vortex-lattice potential flow model is implemented. The nonlinear model of the beam in axial flow is verified against wind tunnel experimental results and a numerical energy flow analysis is employed to determine the distribution of piezoelectric material along the body length. Dynamic strain distribution analysis is then performed to determine the electrode configuration to avoid cancelation of the electrical output.