Effects of higher-order terms in aerodynamic force on the nonlinear response of a galloping PZT energy harvester

In this paper, the effects of higher-order terms in aerodynamic force model have been investigated on the response of galloping piezoelectric energy harvesters. The system comprised a PZT beam with a bluff body and was exposed to a fluid force. First, the dimensionless governing electromechanical equations were provided. To model the aerodynamic force, the 3rd and 7th order galloping models have been employed by adopting the quasi-steady assumption. Then, the dynamic response based on the 3rd and 7th order aerodynamic force models has been studied using a numerical integration method. Besides, an approximateanalytical solution based on the multiple scales method (MSM) has been provided. Next, the mechanical and electrical responses of the system are obtained using the MSM solutions. Finally, the optimum electrical power and the corresponding dimensionless load resistance have been obtained. The results reveal that considering higher-order terms in aerodynamic force expansion is necessary for accurate characterization of the mechanical and electrical responses.