Home » Robotics

Liquid hydrogen and fuel cell powered UAV sets new endurance record

By Damir Beciri
12 May 2013

ion-tiger-flightResearchers at the U.S. Naval Research Laboratory (NRL) broke the endurance record for small electric Unmanned Aerial Vehicles (UAVs) by developing a vehicle powered by liquid hydrogen fuel and a fuel cell. This flight shatters their previous record of 26 hours and 2 minutes set in 2009 using the same vehicle, but with gaseous hydrogen stored at 5000 psi.

Although long endurance is achievable with conventional fuels, hydrocarbon-fueled systems are usually loud, inefficient, and unreliable when it comes to these small flying vehicles. On the other hand, small, electric, battery-powered systems are limited to endurances of only several hours. These are the reasons why NRL researchers started developing UAVs which rely on hydrogen as their source of power.

ion-tiger-team

In order to beat their old record, the researchers opted for liquid hydrogen which is three times denser than 5000-psi compressed hydrogen. The cryogenic liquid is stored in a lightweight tank, allowing more hydrogen to be carried onboard to increase flight endurance. Success in flight requires developing a high quality, lightweight insulated flight dewar for the cryogenic fuel, plus matching the boil off of the cryogenic hydrogen to the vehicle fuel consumption.

“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 Dr. Karen Swider-Lyons, NRL principal investigator.

Named Ion Tiger, the UAV flew for 48 hours and 1 minute on April 16-18 by using liquid hydrogen fuel in a NRL-developed cryogenic fuel storage tank and delivery system.

To address the logistics of in-theater supply of liquid or gaseous hydrogen, NRL proposes in-situ manufacture of LH2 for use as fuel. An electrolyzer-based system would require only water for feedstock, and electricity, possibly from solar or wind, to electrolyze, compress, and refrigerate the fuel.

Tags: , , , , , ,

Leave your response!

Our website is protected by Akismet and any spam or non-related discussion will be blacklisted.

You can use these tags:
<a href="" title=""> <abbr title=""> <cite> <em> <q cite=""> <strike> <strong> <acronym title=""> <blockquote cite="">

If you want your image next to your comments, please register at Gravatar and set your image there.