Damping Characteristic Analysis of an Airflow Energy Harvesting System

Abstract

Abstract With the rapid development of electronic technology, the use of portable and wearable electronics hasbeen widely. In order to eliminate the dependency of low-power electronic devices on batteries and the associated requirement of periodic replacement, researchers have begun investigating methods of generating energy from ambient sources. An airflow energy harvester for human motion is typically composed of a spring-mass system with an air pump connected in parallel with a spring and a turbine. Recent studies have proposed some airflow energy harvesting devices. However, these studies are focused on structural design and little attention has been devoted to the energy conversion process. There are two processes for energy conversion: human motion to airflow energy, then airflow energy to electricity. Focus on the energy conversion, this paper proposes a way to evaluate the energy of the airflow from the perspective of damping at harmonic excitations. The model of an airflow energy harvester for human motion composed of a spring-mass system with an air pump connected in parallel with a spring and a turbine is built, and the balance force analysis is carried out. Comparing the mathematical models and the force analysis equations, the regular pattern of the damping change of the system during the vibration is defined. The simulation isperformed, the result indicates that the energy of the airflow which the vibration system provides is related to the damping of the system. This paper provides a new method toanalyzethe energy conversion process, which helps to measure the efficiency of the airflow energy harvester preferably.