Hydrogen-powered UAV sets new endurance record
Fuelled by liquid hydrogen, the US Naval Research Laboratory's Ion Tiger UAV has flown for a record 48 hours and one minute.
The flight broke the team's previous record of 26 hours and two minutes, which was set in 2009 using the same vehicle. This time, however, the drone was powered by a fuel cell running from liquid hydrogen in cryogenic storage.
"Liquid hydrogen coupled with fuel cell technology has the potential to expand the utility of small unmanned systems by greatly increasing endurance, while still affording all the benefits of electric propulsion," said NRL principal investigator Dr Karen Swider-Lyons.
Although long endurance is possible with conventional, hydrocarbon-fuelled systems, these are usually loud, inefficient, and unreliable in this aircraft class. Similarly, small, electric, battery powered systems are limited to endurances of only several hours.
To address the logistics of in-theatre supply of fuel, Swider-Lyons and the NRL team proposes the in-situ manufacture of liquid hydrogen. "An electrolyser-based system would require only water for feedstock, and electricity, possibly from solar or wind, to electrolyse, compress and refrigerate the fuel," she concluded.
