Dual-mass electromagnetic energy harvesting from galloping oscillations and base excitation

Abstract

This paper investigates electromagnetic energy harvesting based on vibration energy extraction from the vibration of a bluff body elastically connected with an additional nonlinear oscillator and subjected to fluid flow and base excitation. The mechanical part is modeled as a system of two coupled oscillators where a combination of harmonic base excitation and fluid forces leads to a steady-state regime. The electromagnetic generator as part of the harvesting device is represented by the equivalent electrical circuit with power dissipated at an electrical load resistance. The mathematical model is based on a set of two coupled nonlinear ordinary differential equations considering the transverse displacement of a bluff body, additional nonlinear oscillator, and currents induced in the electromagnetic generator. By introducing the incremental harmonic balance and continuation methods nonlinear periodic responses are investigated and complex dynamic behavior presented through corresponding response diagrams. The results indicate that for some values of system parameters multiple periodic solutions appear in the form of loops and hysteresis. Finally, the average power of proposed energy harvester is given in time history diagrams for different values of nonlinear stiffness parameter and velocity of fluid flow.