Aircraft

AeroDelft's Phoenix rising as the world's first liquid-hydrogen aircraft

AeroDelft's Phoenix rising as ...
AeroDelft has revealed a one-third scale prototype of its Phoenix two-seater, which aims to be the world's first liquid hydrogen plane
AeroDelft has revealed a one-third scale prototype of its Phoenix two-seater, which aims to be the world's first liquid hydrogen plane
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AeroDelft has revealed a one-third scale prototype of its Phoenix two-seater, which aims to be the world's first liquid hydrogen plane
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AeroDelft has revealed a one-third scale prototype of its Phoenix two-seater, which aims to be the world's first liquid hydrogen plane
The Phoenix retro-fits a hydrogen energy storage system and fuel cell to the e-Genius electric glider
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The Phoenix retro-fits a hydrogen energy storage system and fuel cell to the e-Genius electric glider
The full-size Phoenix will have an endurance up to 10 hours, and range up to 2,000 km on a full 10-kg tank of liquid hydrogen
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The full-size Phoenix will have an endurance up to 10 hours, and range up to 2,000 km on a full 10-kg tank of liquid hydrogen
A sleek and attractive electric glider design
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A sleek and attractive electric glider design
The 1:3 scale prototype was revealed in an online presentation
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The 1:3 scale prototype was revealed in an online presentation
Members of the 44-person AeroDelft team with the scale prototype
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Members of the 44-person AeroDelft team with the scale prototype
The prototype will fly first with battery power, then using gaseous hydrogen, and finally, toward the end of the year, with liquid hydrogen
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The prototype will fly first with battery power, then using gaseous hydrogen, and finally, toward the end of the year, with liquid hydrogen
The Phoenix prototype is aiming for a 500-km range and 7 hours of endurance on a kilogram of liquid hydrogen
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The Phoenix prototype is aiming for a 500-km range and 7 hours of endurance on a kilogram of liquid hydrogen
The Greenliner would scale things up to a 19-seat liquid hydrogen-powered airliner
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The Greenliner would scale things up to a 19-seat liquid hydrogen-powered airliner
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We've written plenty about hydrogen's potential as a transformative technology for green aviation; in gaseous form, hydrogen offers an energy density much higher than lithium batteries, and that offers a genuine path toward the decarbonization of short-to-medium range air travel.

But the biggest planes are the biggest emitters, and to eliminate emissions from long-range airliners, compressed gas hydrogen systems – which offer about half the range of an equivalent jet fuel powertrain – will never be able to do the trick. For that, we're going to need liquid hydrogen systems.

Liquid hydrogen systems can store upwards of three times the energy by weight of a gaseous system, meaning that a large-scale liquid hydrogen airliner could conceivably fly farther than today's fossil burners.

It's not quite that simple. Liquid hydrogen has terrific energy density by weight, but terrible density by volume, so you'd need to design your aircraft with significantly more fuel storage space and potentially deal with additional drag as a result. But it may be one of the only clean fuel technologies that can get zero-emission intercontinental airliners into mainstream use in the medium term.

All of which makes this pioneering work from AeroDelft very exciting indeed. A team of 44 students from TU Delft in the Netherlands has been beavering away on the "world's first liquid hydrogen fuel cell aircraft," and has now presented a 1/3-scale prototype that is scheduled for its first public flight this July.

Members of the 44-person AeroDelft team with the scale prototype
Members of the 44-person AeroDelft team with the scale prototype

The Phoenix will be a hydrogen-retrofitted version of the two-seat e-Genius electric glider, developed at the University of Stuttgart and first flown in 2011. The e-Genius has flown over 400 km (250 miles) in its record-breaking history on battery power alone. It can get around 1,000 km (620 miles) using a petrol-powered range extender. The full-sized Phoenix will carry 10 kg of liquid hydrogen, with an estimated range of 2,000 km (1,240 miles) and an endurance up to 10 hours in the air.

The one-third scale, remote-controlled prototype is not small; it's got a 5.7-m (around 19-ft) wingspan, weighs 50 kg (110 lb) and carries 1 kg (2.2 lb) of liquid hydrogen, enough for an estimated endurance around 7 hours and a range around 500 km (310 mi). The hydrogen is kept in a cryogenic tank at -253 °C (-423 °F), and warmed up to 0 °C (32 °F) using "a complex tubing system" before being run through a 1.5-kW fuel cell to charge a buffer battery that powers the electric propeller motor on the aircraft's tail.

The AeroDelft team plans to fly the Phoenix this July on battery power, then on gaseous hydrogen a few months later, and finally, somewhere around (Northern Hemisphere) Fall this year, the students will fit the liquid hydrogen system.

The Phoenix retro-fits a hydrogen energy storage system and fuel cell to the e-Genius electric glider
The Phoenix retro-fits a hydrogen energy storage system and fuel cell to the e-Genius electric glider

"Development of the liquid hydrogen system is going swimmingly," said Prototype Project Manager Sam Rutten. "We're ending the design phase. Liquid hydrogen is a very difficult thing to work with. For it to stay liquid, you need to cool it to around 20 Kelvin, very close to absolute zero. Our Propulsion team has developed a special tank, and also other support systems, which will allow us to fly with liquid hydrogen. We're already starting the production phase, the first steps have already been taken to construct this tank according to all the relevant certification."

The full-size two-seat Phoenix is also already being built, with a reveal scheduled for July. It should fly on gaseous hydrogen by summer 2022, and the first full-scale liquid hydrogen flight is planned for 2024. Both the prototype and the full-size Phoenix stand to set all kinds of records, but the project is also focused on advancing hydrogen aviation by working with certification boards to develop a framework within which a liquid hydrogen aircraft can be certified, identifying risks related to liquid hydrogen aviation and working out systems to help mitigate them.

Commercializing the Phoenix is not on the team's radar at this point, although it's happy to speak to anyone who'd like to take that on. AeroDelft does have plans for a larger scale aircraft though, including a liquid hydrogen airliner capable of flying 19 passengers plus pilots up to 925 km (570 mi), which it calls the Greenliner. There are technical mountains to climb with the Phoenix, however, before the Greenliner project gets too far along.

The Greenliner would scale things up to a 19-seat liquid hydrogen-powered airliner
The Greenliner would scale things up to a 19-seat liquid hydrogen-powered airliner

The Phoenix is a very exciting project in a field that has genuinely transformative potential. The world needs liquid hydrogen to advance in leaps and bounds if we're to eliminate the roughly 2 percent of global greenhouse gas emissions contributed by the aviation sector. It's terrific to see the Delft team making significant progress, and we look forward to following the Phoenix through the remainder of the project.

Check out the prototype launch presentation below.

Prototype Model Reveal

Source: AeroDelft via Robb Report

View gallery - 9 images
13 comments
13 comments
Peter Forte
Truly exciting developments!!
paul314
Current airplane design is very much based on history and the needs of jet engines, so it will be interesting to see what they come up with.
Chris Coles
While not enjoying being seen as negative to any new thinking; as I see thing, liquid hydrogen will not succeed as a fuel. It is difficult to store, is incredibly dangerous, as anyone familiar with space rockets will know, hydrogen can be very explosive. Now add that every time flown, all the hydrogen gas will have to be drained off the aircraft, as even storing the aircraft outside will carry risks of leaks and resulting explosions. Then add, these uses will not be the occasional flight; a hydrogen leak on an active airfield will, almost certainly; close the airfield down until all gas has been dispersed . . . and checked to be so. While on paper a great idea, sadly, the use of hydrogen gas to replace more complex hydrocarbons will never become widespread . . . there are simply too many risks involved.
Chris Coles
And to add, all such hydrogen storage involving liquid hydrogen will have, as we always see with rockets, substantial flows of gas being vented, as it is impossible to keep anything stored at - 253 Degrees C without a suitable system to allow excess gas flow caused by the gas stored boiling off to be continuously vented to the surrounding atmosphere.
buzzclick
If this energy storage system has merit, we will see it developed over the next decade, but what Chris Cole says about the pressures of storage tanks and having to keep them at near Kelvin temps will certainly be a huge challenge. It's like designing a battery from components in dynamite. There's little room for error and for heaven's sake be careful. Are you sure you want to try this?
Finding ways to produce hydrogen economically and effective ways to store it is key.
Derek Howe
This project won't go anywhere meaningful.
Arcticshade
And once again the armchair trolls have not read the article, thinking they know more than the engineers pioneering this technology.

Sorry for those clinging on to caveman mentality, the future is unfolding and the future sits right here in this very article.

Well done Aerodelft, this technology is going to be an absolute successor to the troubling fossil fueled industry plaguing the planet.
FB36
Hydrogen is explosive & so it is really bad idea to use as fuel for any aircraft/vehicle!
Right solution for making all aircraft is the same for all heavy trucks, trains, ships etc:
Start producing biodiesel/biofuel from all kinds of waste/biomass/trash/sewage!
Arcticshade
@FB36

Yet Another TROLL not reading the article nor understanding Hydrogen Technology and how far Aerodelft have come.

Go sit with your fellow flat earth thinkers in a cave somwhere and ponder about the next stone age invention, we living in the 21 st century will continue to make heaps of progress on the latest technology. GO AERODELFT ! ! !
JimFox
Derek Howe has nothing to contribute, so why bother commenting?
FB36 has not read the article so his comment is worthless.

Arctic shade is 100% correct, well done.
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