LINEAR AND NONLINEAR AEROELASTIC ENERGY HARVESTING USING ELECTROMAGNETIC INDUCTION

摘要

Transforming aeroelastic vibrations into electricity for low-power generation has received growing attention over the past couple of years. The goal is to convert wind energy into electricity for powering small electronic components employed in wireless applications such as structural health monitoring. The potential applications of interest for aeroelastic energy harvesting range from lifting components in aircraft structures to several other engineering problems involving wireless electronic components located in high wind areas. This paper investigates linear and nonlinear aeroelastic energy harvesting using electromagnetic induction. A two-dimensional airfoil with plunge and pitch degrees of freedom (DOF) is considered. The electromagnetic induction is introduced to the plunge DOF by means of a coil-magnet combination and the nonlinearities are introduced through the pitch DOF. The governing dimensionless aeroelastic equations are given with electromagnetic coupling and a resistive load in the electrical domain. The effects of several dimensionless system parameters (electromechanical coupling, load resistance, and coil inductance) on the dimensionless electrical power as well as the dimensionless linear flutter speed are investigated. After considering the linear problem, combined nonlinearities are investigated to improve the electrical output. A cubic stiffness of the hardening type is combined with the free play nonlinearity to make the resulting nonlinear oscillations bounded with acceptable amplitude over a wide range of airflow speeds. The results and the dimensionless simulations presented in this work can be employed for designing and optimizing scalable aeroelastic energy harvesters for wind energy harvesting using electromagnetic induction.