Researchers at the City College of New York are developing a new way to generate power for planes and road vehicles, which would source electricity from air flow.
Using short, flexible piezoelectric cantilever beams which convert the kinetic energy of motion into electricity, the researchers believe the power generated could scavenge otherwise wasted energy from the environment.
Their idea was presented at the 62nd Annual Meeting of the American Physical Society’s Division of Fluid Dynamics at the Minneapolis Convention Centre. The researchers experimentally investigated devices placed inside turbulent wakes of circular cylinders at Reynolds numbers of 10,000 and found that the power could run some systems, such as batteries, that would be used to charge control panels and small electronic devices.
When the device is placed in the wake of a cylinder the flow of air causes the devices to vibrate in resonance. On the roof of a car, they would shake in a more unsteady flow known as a turbulent boundary layer.
Two mechanisms contribute to the driving force – the first is the impingement of induced flow and the second is the low pressure core region which is present at the opposite side of the beam. When they combine, the beam generates maximum energy output that varies dependent on the location of the wake.
