An indoor air duct flow energy conversion system: modeling and experiments

This paper presents an indoor, low-speed airflow, energy harvesting system based on aerodynamic flutter. Due to aerodynamic forces, mechanical vibrations occur when airflow passes across flexible belt-like structures. A linear electromagnetic generator has been designed to transfer this mechanical power into electricity based on Faraday's law. Based on a model which couples the aerodynamic flutter with the electromagnetic generator, the output electrical power can be estimated and optimized. The airflow from an air duct with a 0.5m × 0.5m cross-sectional area is used to drive an energy conversion device in experiments. The experimental results show that this prototype flutter energy conversion device (FECD) could provide nearly 2VRMS voltage with a 2.5m/s airflow. A set of super capacitors is used as a temporary storage element. With a power management circuit, the entire energy harvesting device can operate as a stable 3.3V DC power source during a discharging cycle.