The Multi-Harmonic Excitation Characteristic Of Airflow Piezoelectric Generator

In order to improve the adaptive range of airflow velocity, an airflow piezoelectric generator based on multi-harmonic excitation is proposed. The flow field characteristics are obtained by CFD method, the acoustic vibration characteristics and variation with velocity of the excitation frequency are studied. The result shows that periodic compression and expansion of air are presented and a standing wave is formed inside the resonator, which can provide stable excitation source. The excitation frequencies are distributed on the acoustic modes of the resonator and captured. With different velocity segment, the excitation frequencies are different, and frequency conversion is presented from the first-order to the third-order and from the third-order to the first-order. The conclusions verify the feasibility of the multi-harmonic excitation energy exchange scheme, which is helpful to improve the flow velocity adaptive range of the airflow-induced vibration piezoelectric generator.