Electric and Hydrogen aeroplanes - feasibility and issues

"A lot of things have been written off in the past but times and technologies change. I can remember so called experts claiming video calls were impossible too. "

I'm still waiting for the anti-gravity and time machines.
 
A leaking gasoline tank is a lot more dangerous than a leaking hydrogen tank.

Hydrogen, unlike gasoline, methane and pretty much everything else, will leak out of a closed container by permeating right through the tank walls.
 
Another disadvantage of hydrogen is that currently the cheapest production method involves "cracking" petro-chemicals. We really need a more efficient method of electrolysis to make it economical.
 
Another disadvantage of hydrogen is that currently the cheapest production method involves "cracking" petro-chemicals. We really need a more efficient method of electrolysis to make it economical.

Density is horrible, 2.5 less than all you mentionned. Making wing tanks impossible and thus LH2 has to go in the fuselage. Uncomfortably close from the passenger cabin. With below characteristics...
Temperature is horrible, - 270°C to keep hydrogen liquid.
Boiloff is a huge PITA
And the non negligible risks of explosion if too much gaseous hydrogen in the near atmosphere.
...
REL process for ammonia aircraft looks much less risky if only because NH3 properties are so much closer from Jet-A.
 
I shudder at the thought of 10 000+ hydrogen cars per day on my town motorway - Bordeaux, which is on the top three french cities for both traffic and arseholes lunatic drivers - only behind Marseille and Paris...
Electric hybrid methanol or ammonia cars, maybe, but LH2 ? Over my dead body !
 
A leaking gasoline tank is a lot more dangerous than a leaking hydrogen tank. Gasoline tends to pool underneath the car and vapors can easily mix with the air, which is why its used in the movie industry for all those nice Michael Bay explosions. Hydrogen being lighter than air will rise and tends to diffuse making it hard to reach the right concentrations to explode. Also a hydrogen fireball will rise as seen in the Hindenburg disaster (which saved a lot of the passengers and crew) while a gasoline fireball will stick close to the ground. As far as safety goes, I'll take a hydrogen car over a gasoline car any day.

BTW the Hydrogen disaster was primarily caused by its incredibly flammable skin (akin to thermite) more than its hydrogen filled bladders.
This, happily, is completely false; it was a piece of fake news put about by one developer of airships to deflect concerns about the safety record of hydrogen. The aluminiumised fabric used on the Hindenburg is about as dangerous as the metal in an aluminium drinks can; demonstrations have been done wuth surviving samples from the Hindenburg and even a gas torch didn't ignite it; you won't get it to burn unless you grind it into a powder and mix it with rust....

SRJ.
 
The introduction of Liquid Hydrogen into service on aircraft would require a massive amount of reworking of taxiways and gates at airports, as aircraft would need to be built larger. This would probably be down to either using external tanks, or a completely separate fuselage. Either way, something must be done.
 
Well, structural holding of LH2 is the goal we have to reach. We had a lot of metallic foams R&D only a decade ago for example that stalled with the predominance of composite and all the buzz words that came with it. But ideally a foam (any type by the way) can be seen as the ideal holding tank.
Then there are all the substitutes chemicals transports of LH2 that still hold a significant portion of Hydrogen easily available (ammonia (liquid or in grain)).
The road is long before any Airport modification
 
Bye Aerospace Unveils 8-Seat All-electric eFlyer 800

DENVER, Colorado – April 22, 2021 – Bye Aerospace has announced an eight-seat all-electric twin turbo-prop class airplane, the eFlyer 800™, in response to growing demands for regional all-electric airplanes with significantly reduced operating costs, plus increased capacity and utility.

Performance estimates for the eFlyer 800 include up to 320 knot cruise speed, 35,000 feet ceiling and 500 nm range with 45-minute IFR reserves at normal cruise speed of 280 knots. Safety features include two wing-mounted electric motors, each with dual redundant motor windings, quad-redundant battery packs and a full airplane parachute. Additional potential features include emergency auto-landing system, intelligent algorithm ensuring envelope protection, terrain avoidance and routing for emergency auto-land, and also an option for supplemental power solar cells and in-wheel electric taxi. The airplane’s 8-seat configuration consists of up to seven passengers and one or two pilots. The eFlyer 800 will have only one-fifth the operating costs of traditional twin turboprops and is geared for the air-taxi, air-cargo, regional and charter aircraft markets.

“The eFlyer 800 is the first all-electric propulsion technology airplane that achieves twin-turboprop performance and safety with no CO2 and extremely low operating costs,” said George E. Bye, Bye Aerospace CEO. “This type of remarkable economy and performance is made possible by the electric propulsion system and advanced battery cell technology that results in significantly higher energy densities.”

Bye Aerospace and Safran are currently assessing the most efficient electric powertrain for the eFlyer 800 (dual ENGINeUS™ electric motors and GENeUSGRID™ electric distribution and network protection system). “Safran product lines with the ENGINeUS™ motors, rated from 50kW to 500kW/1MW and GENeUSGRID™ systems, perfectly fit with the Bye Aerospace portfolio of e-aircraft,” said Hervé Blanc, Executive Vice President and General Manager Power with Safran Electrical & Power. “Building upon our successful cooperation on eFlyer2 and eFlyer4, we are very proud to bring our best expertise to support Bye Aerospace in the design of the new eFlyer 800.”

Bye said eFlyer 800 customer deposit agreements are complete, and several are being developed with U.S. and European air-taxi, air-cargo and air charter services. “Details about those agreements will be announced soon, and as they are finalized,” he said.

Bye Aerospace is in the process of obtaining FAA Part-23 certification for the eFlyer 2 for the professional flight training mission and the four-seat eFlyer 4 for air taxi, cargo and advanced training uses. All the company’s current and future families of aircraft feature engineering, research and electric aircraft solutions designed to specifically address compelling market needs. Benefits include five-fold lower operating costs, no CO2 emissions, and decreased noise. Bye Aerospace estimates the eFlyer will eventually eliminate the release of millions of metric tons of CO2 each year as its deliveries begin and the general aviation fleet is replaced.

bye-aerospace-eflyer-800-concept-jpg.620785


 
Battery energy density is the issue. The current health crisis, along with competition, has delayed the announcement of new developments in solid state battery technology. But one company has recently emerged from stealth mode.

 
View: https://twitter.com/AviationWeek/status/1397326566741381122



 
I have personal experience with Honeywell's generators. I can only say I hope they have gotten better.
 
Here comes a new challenger~~

So how does this tech look? I'm looking at 8.1 kg unit storing 0.252 kg of H2 from one of the slides, but no pressurization, maintaining low/high temperatures and all that.
 
The Danish defense ministry said Thursday that it will lease two electric trainer airplanes as a test, adding that it is the first country in the world to do so.

The single-engine, two-seater Pipistrel Velis Electro is an electric-powered Slovenian light aircraft intended primarily for training use. It will complement the Danish air force’s current training aircraft, the Saab T-17 Supporter, which is used for school flights and maintenance training flights.
 
Rolls-Royce has started testing the first elements of the most powerful hybrid-electric aero power and propulsion system in aerospace at a newly-renovated testbed.

The tests are part of the 2.5 megawatt (MW) Power Generation System 1 (PGS1) demonstrator programme, for future regional aircraft.

Rolls-Royce has begun testing the AE2100 engine element and specialist controls and thermal management system, supported by a system integration generator, at our Testbed 108 in Bristol, UK.


 
“I have a fair amount of experience with hydrogen, our company has an incredible amount of experience with hydrogen. At least in the size of airframe that we are all talking about. We experiment at the low end, but that’s not going to be a meaningful market here,” Calhoun US-based company’s president and CEO, said

 
No pure hydrogen. My bet would be on either hybrid-electric or hydrogen-cracked-into-ammonia (to try and get the best of both).
 
Meanwhile that strange idea (LH2) would have been a cash cow..

(edited)
 
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PARIS, France - June 14, 2021 - GE Aviation and Safran today launched a bold technology development program targeting more than 20 percent lower fuel consumption and CO2 emissions compared to today's engines. The CFM RISE (Revolutionary Innovation for Sustainable Engines) program will demonstrate and mature a range of new, disruptive technologies for future engines that could enter service by the mid-2030s.
• CFM RISE* program targets more than 20 percent lower emissions
• Program will include open fan architecture, hybrid electric capability, demonstrator ground and flight tests around middle of decade
• 100 percent Sustainable Aviation Fuel, Hydrogen capability in scope
View: https://twitter.com/GEAviation/status/1404437072241385473

View: https://www.youtube.com/watch?v=0YsEHqlh9C0

 
Meanwhile that strange idea (LOX) would have been a cash cow...

Can you elaborate? I'm having a hard time thinking of a way LOX can be used to reduce emissions or energy usage in airliners.
 
Sure, technically eSTOL is a lot closer and more credible than eVTOL.
I wish the Airflow website did not make me so skeptical...
 
The Director of the Air Academy (France) express his scepticism regarding Airbus vaunted EU subsidized hydrogen research for aviation, urging political bodies to pursue a more realistic approach:

 
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PARIS, France - June 14, 2021 - GE Aviation and Safran today launched a bold technology development program targeting more than 20 percent lower fuel consumption and CO2 emissions compared to today's engines. The CFM RISE (Revolutionary Innovation for Sustainable Engines) program will demonstrate and mature a range of new, disruptive technologies for future engines that could enter service by the mid-2030s.
• CFM RISE* program targets more than 20 percent lower emissions
• Program will include open fan architecture, hybrid electric capability, demonstrator ground and flight tests around middle of decade
• 100 percent Sustainable Aviation Fuel, Hydrogen capability in scope
Does this mean the propfan is coming back?
 

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