The Naval Research Laboratory's Ion Tiger, a
hydrogen-powered fuel cell unmanned air vehicle (UAV), has flown 23 hours and
17 minutes, setting an unofficial flight endurance record for a fuel-cell
powered flight. The test flight took place on October 9th through 10th at
Aberdeen Proving Ground. The Ion Tiger fuel cell system development team is led
by NRL and includes Protonex Technology Corporation, the University of Hawaii,
and HyperComp Engineering. The program is sponsored by the Office of Naval
Research (ONR).
The electric fuel cell propulsion system onboard the Ion
Tiger has the low noise and signature of a battery-powered UAV, while taking
advantage of hydrogen, a high-energy fuel. Fuel cells create an electrical
current when they convert hydrogen and oxygen into water, with only water and
heat as byproducts. The 550-Watt (0.75 horsepower) fuel cell onboard the Ion
Tiger has about 4 times the efficiency of a comparable internal combustion
engine and the system provides 7 times the energy in the equivalent weight of
batteries. The Ion Tiger weighs approximately 37 pounds and carries a 4 to 5
pound payload.
Small UAVs are growing in importance for naval missions, as
they provide capabilities ranging from surveillance collection to communication
links. Electric UAVs have the additional feature of being nearly undetectable
from the ground. Due to the high energy in the fuel cell system onboard the Ion
Tiger, it is now possible to do long endurance missions with an electric UAV,
thus allowing a larger cruise range and reducing the number of daily launches
and landings. This provides more capability while saving time and effort for
the crew.
In 2005, NRL backed initial research in fuel cell
technologies for UAVs. Today, says NRL's Karen Swider-Lyons, "the long
endurance flight was made possible by the team's research on high power,
efficient fuel cell systems, lightweight hydrogen-gas storage tanks, improved
thermal management, and the effective integration of these systems."
Fuel cell technology is being developed to impact the
operational spectrum of technologies including ground, air and undersea
vehicles and man-portable power for Marine expeditionary missions. "The
Ion Tiger successfully demonstrates ONR's vision to show how efficient, clean
technology can be used to improve the warfighter's capabilities," comments
ONR's Michele Anderson.
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