Simulation of Aeroelastic Instabilities to Evaluate the Power Output of Flutter-based Electromagnetic Energy Harvesters

摘要

The unstable vibration of flexible T-shaped cantilever systems due to the aeroelastic instabilityrnphenomena like flutter can be used as an effective input source for small-scale energy harvesting.rnThe extracted environmental energy of a vibrating system can be converted into electrical powerrnusing an electromagnetic transducer. The paper presents a two-dimensional fully coupled CFDrnsolverfor simulatingthe flutter induced vibration ofa T-shaped prototypeharvester to model thernpower output numerically. A flow solver based on Vortex Particle Method and a structural solverrnusing Finite Element formulationsare coupledefficiently to model the unstable vibration of therncantilever harvester.Theoretically, a structural systembecomes unstable and exhibits flutterrnphenomena when the negative aerodynamic damping exceeds the total system damping. However,rnfor electromagnetic harvester, the total system damping is the sum of the mechanical damping andrnthe additional electrical damping from electromagnetic transducer. The CFD simulations arernperformed to find the critical onset flutter wind speed and the results are compared with wind tunnelrntest results for model validation. The critical electrical load resistances for onset of flutter are alsornidentified for different wind speeds and compared withthe wind tunnel results. Finally, the voltagernand power output of the harvester under different wind speeds and electrical load resistances arernmodeled, compared and modifications on the harvester system are done to increase power output.