Cars, planes could boost power with energy-scavenging devices

A group of researchers in the US is envisioning a future in which small devices on planes and automobiles could “scavenge” kinetic energy to generate electricity for control panels and other uses.

The team from the City College of New York (CCNY) is presenting its concept for such piezoelectric devices, which convert motion energy into electricity, at this week’s annual meeting of the American Physical Society in Minneapolis.

About a half-inch by one inch in size, these devices might be mounted on the roof or tail of a car or on an airplane fuselage, where they would vibrate inside a flow, producing an output voltage. The power generated would not be enough to replace that supplied by the combustion engines, but it could run some system — such as batteries that would be used to charge control panels and other small electronic devices such as mobile phones.

Led by CCNY professor Yiannis Andreopoulos, the researchers are currently attempting to optimise these devices by modeling the physical forces they encounter in different air flows — on the roof of a car, for instance, or on the back of a truck.

When the device is placed in the wake of a cylinder — such as on the back of a truck — the flow of air will cause the devices to vibrate in resonance, Andreopoulos said. On the roof of car, the device will shake in a much more unsteady flow known as a turbulent boundary layer.

During this week’s meeting, Andreopoulos and his colleagues will present wind tunnel data showing how the devices work in both situations.

“These devices open the possibility to continuously scavenge otherwise wasted energy from the environment,” Andreopoulos said.