Tomorrow’s aircraft could contribute to their power needs
by harnessing energy from the wheel rotation of their landing gear to generate
electricity.
They could use this to power their taxiing to and from
airport buildings, reducing the need to use their jet engines. This would save
on aviation fuel, cut emissions, and reduce noise pollution at airports.
The feasibility of this has been confirmed by a team of
engineers from the University
of Lincoln with funding
from the Engineering and Physical Sciences Research Council (EPSRC).
The energy produced by a plane’s braking system during
landing—currently wasted as heat produced by friction in the aircraft’s disc
brakes—would be captured and converted into electricity by motor-generators
built into the landing gear. The electricity would then be stored and supplied
to the in-hub motors in the wheels of the plane when it needed to taxi.
‘Engine-less taxiing’ could therefore become a reality.
ACARE (the Advisory Council for Aeronautics Research in Europe)
has made engineless taxiing one of the key objectives beyond 2020 for the
European aviation industry.
“Taxiing is a highly fuel-inefficient part of any
trip by plane with emissions and noise pollution caused by jet engines being a
huge issue for airports all over the world,” says Professor Paul Stewart,
who led the research.
“If the next generation of aircraft that emerges
over the next 15 to 20 years could incorporate this kind of technology, it
would deliver enormous benefits, especially for people living near airports.
Currently, commercial aircraft spend a lot of time on the ground with their
noisy jet engines running. In the future this technology could significantly
reduce the need to do that.”
The University
of Lincoln’s research
formed part of a project that aimed to assess the basic feasibility of as many
ways of capturing energy from a landing aircraft as possible.
“When an Airbus 320 lands, for example, a
combination of its weight and speed gives it around three megawatts peak
available power,” Professor Stewart explains. “We explored a wide
variety of ways of harnessing that energy, such as generating electricity from
the interaction between copper coils embedded in the runway and magnets
attached to the underside of the aircraft, and then feeding the power produced
into the local electricity grid.”
Unfortunately, most of the ideas weren’t technically feasible
or simply wouldn’t be cost effective. But the study showed that capturing
energy direct from a plane’s landing gear and recycling it for the aircraft’s
own use really could work, particularly if integrated with new technologies
emerging from current research related to the more-electric or all-electric
aircraft.
A number of technical challenges would need to be
overcome. For example, weight would be a key issue, so a way of minimizing the
amount of conductors and electronic power converters used in an on-board energy
recovery system would need to be identified.
The project was carried out under
the auspices of the EPSRC-funded Airport Energy Technologies Network (AETN)
established in 2008 to undertake low-carbon research in the field of aviation,
and was undertaken in collaboration with researchers at the University of Loughborough.
