Airbus and Rolls-Royce hit eject on hybrid-electric airliner testbed after E-Fan X project fails to get off the ground

Airbus and Rolls-Royce have ended a joint venture to produce a hybrid-electric airliner testbed that could have paved the way for electric aircraft of the future. Airbus CTO Grazia Vittadini said in a statement late last week that "we need to re-focus all of our efforts on technology 'bricks' that will take us" to a low-CO2- …

[Chris G]

If it doesn't get off the ground

I can see a future in in shipping for a generator like that.

[Holtsmark]

It may be worth noting that the Siemens electric aircraft propulsion unit was aquired by Rolls Royce in October 2019

https://www.rolls-royce.com/media/press-releases/2019/01-10-19-rr-completes-acquisition-of-siemens-electric-and-hybrid-electric-aerospace-propulsion.aspx

This means that Siemens position in the project is irrelevant.

[Tubz]

beer keg, not that big, make a mini version for a vehicle, may be trucks ?

[Vulch]

2.5MW would make a respectable railway locomotive by the look of it.

[Cynic_999]

Engines are not trivially scalable, and in any case a jet engine can have problems in a ground vehicle due to the considerable centrifugal forces of the high speed turbines causing problems when cornering. Although those can be alleviated by mounting it vertically.

[CliveS]

In the UK, for railway use, I would draw your attention to British Rail 18000 and 18100, and to the APT-E, all gas turbine powered and the first completed in 1949. As regards road usage, I'd like to mention the Rover JET1 (1949), Fiat Turbina (1954), Chrysler Turbine Car (1963), Toyota GTV (1987) and Jaguar C-X75 (2010) as examples of gas turbine installations in practical cars.

[Yet Another Anonymous coward]

Or a motorbike

[Cynic_999]

In fact you *make* my point rather than refute it.

There are good reasons why none of the turbine cars you mention were successful, and AFAIAA there is not a single turbine car or locomotive that went into mass production or are available today.

[CliveS]

Please, re-read your own post before being so daft as to claim I *make* your point. I'll help you out:

"Engines are not trivially scalable, and in any case a jet engine can have problems in a ground vehicle due to the considerable centrifugal forces of the high speed turbines causing problems when cornering. Although those can be alleviated by mounting it vertically."

The "considerable" centrifugal forces obviously aren't, as none of the examples mentioned had a) any cornering issues, or b) turbines mounted vertically. Scalability isn't a problem either, as there are plenty of examples of gas turbine applications ranging from the micro-turbines used in the C-X75 through to the larger turbines used in the Rover JET1 and APT-E.

There is an issue, one you completely fail to mention, which is throttle response on gas turbine/mechanical drive systems. It was this that caused issues with the JET1 (for example). The Jaguar C-X75 didn't go in to production as the market for an £800,000 - £1,000,000 million niche supercar was considered non-existent in 2010, less than 2 years after the financial crash.

APT-E worked fine, with the gas turbines driving electrical generators, but was not adopted for production as Leyand stopped manufacture of the turbine it used. An additional concern was that BR have had to maintain a fleet of diesel, electric, and gas turbine powered rolling stock. The same issue that caused BR to eventually scrap diesel-hydraulic locomotives and instead use diesel-electric. In France SNCF operated the Turbotrains, two classes of turbine powered trains that were production models rather than one-off prototypes.

The issues around the widespread adoption of gas turbines comes down to infrastructure and economics. So yes, there were good reasons why none of the vehicles mentioned went in to production. However those reasons had absolutely nothing to do with the points you made.

[Yet Another Anonymous coward]

The APT project's problems were beyond anything to do with the turbine.

I wonder how practical a mass-produced turbine hybrid car engine would be?

A small 50-100Hp turbine with an integrated brushless type generator, so you don't have to make a 20,000rpm gearbox. It could run at a constant speed/load just charging the battery

Safety containment shouldn't be any harder than a turbo. Modern control is trivial (lab turbo molecular pumps run at 100K rpm safely) . They can burn pretty much any fuel and should be hot enough to have very little particle exhaust.

[Anonymous Coward]

I wonder how practical a mass-produced turbine hybrid car engine would be?

A small 50-100Hp turbine with an integrated brushless type generator, so you don't have to make a 20,000rpm gearbox. It could run at a constant speed/load just charging the battery

That was the Jaguar model. Worked, but was a tad pricey.

[Yet Another Anonymous coward]

True but a lot of features debut on ludicrous hyper-cars and are then standard on a hatchback a decade later

[jake]

"True but a lot of features debut on ludicrous hyper-cars and are then standard on a hatchback a decade later"

A bad ride, evil handling, eats tires and brakes, 'orrible controls, uncomfy seating, impossible to work on wiring and drivetrain, bad lighting (inside and out), entirely too noisy/buzzy for long trips, not worth anything near what you paid for it ... You're right! A cheap hatch IS an awful lot like most so-called "hypercars"!

[SImon Hobson]

A small 50-100Hp turbine with an integrated brushless type generator

It wouldn't have to be that big as part of a hybrid with energy storage.

For cruising, the power requirements for most cars would be lower than that - and keeping to a lower output genny while using stored energy (batteries and/or supercaps) for higher requirements would reduce the need for throttling back the genny. That's one of the big issues with gas turbines - they work best at fixed (or only slowly changing) power outputs. Configuring the system such that it ran almost all the time at a set power level would mean it could be carefully optimised (efficiency, emissions) for that.

[itzman]

small gas turbines

are inefficient due to the problems in getting micro scale gas turbines efficient because getting the clearance between turbine blades and the ducting small enough is very very hard

[cheb]

There was also LMS Turbomotive built in 1935.. From what I've read it was successful, but uneconomic to rebuild when it failed in 1949.

[Dr Who]

So ... the shit hit E-Fan then

[John Brown (no body)]

E-Fan Gum. The Yorkshire version.

[Anonymous Coward]

Cost saving

Rolls-Royce is stopping all projects they can, due to the fact no engine maintenance is being sold. They need to save at least £750 million this year and the the “headwind” caused by the Covid-19 outbreak so far was approximately £300 million.

[Phil O'Sophical]

Electric planes?

Can anyone explain why an electric plane would be a good idea? Aircraft are far more sensitive to weight than any other form of travel, so hauling a set of batteries around as dead weight just doesn't seem logical. Not to mention that recharging an aircraft during the typical 2 hour turnaround would be a challenge. Even with a super-small generator as described here, where's the benefit over just using the fuel to feed a turbine engine directly, instead of carrying fuel + generator + engine?

For environmental concerns, I'd have thought that air travel would be a prime target for hydrogen or alcohol fuel, which could be obtained from sustainable sources & consumed in a largely-standard engine (turbo-fan or turbo-prop). Since the journeys are well-known in advance, and they always start and end in places with refuelling infrastructure, the logistics would seem easier.

It's a genuine question, I'm not an aero engineer but I struggle to see the benefits of electrical propulsion beyond the "look how clever my engine is" bragging rights.

[Anonymous Coward]

Re: Electric planes?

They tried hydrogen - it had some drawbacks!

[Anonymous Coward]

Re: Electric planes?

The Hindenberg burned because of the dope-covered fabric, all the hydrogen dissipated upwards and burned off mostly harmlessly. It's certainly safer than crashing with tanks full of JET-A1.

[Giles C]

Re: Electric planes?

Well I would guess that if you can power the planes by electric motors, then if someone comes up with some really efficient solar panels you could be on the way to a free fuel situation.

Thinking about it if the panels are good enough then as long as you are flying in daytime almost zero cost. Flying at night might be a bit trickier....?

[David M]

Re: Electric planes?

Electric batteries are about fifty times the mass of airline fuel for a given amount of energy. Plus the batteries aren't consumed during flight, so the landing mass is the same as at take-off. And solar doesn't help - a panel the size of the aircraft would only produce a tiny fraction of the required energy.

The only realistic way to reduce airline fossil fuel consumption at the moment is to fly a lot less. And we're currently proving that this is perfectly viable.

[batfink]

Re: Electric planes?

Speak for yourself. We split our time between the UK and Aus for family reasons. It's not "perfectly viable" to do this any other way than by air travel, given the limited amount of available holiday time.

[BebopWeBop]

Re: Electric planes?

You are going to have to get that Yachtmaster certificate then!

[Cynic_999]

Re: Electric planes?

"

And we're currently proving that this is perfectly viable.

"

Hmmmm. Do you also believe that we are currently proving that we don't need restaurants, pubs or sporting events? Or that over half the population can stop working altogether? Or that we don't need to treat cancer or many other serious conditions?

Just because something is possible to do for a limited time does not mean that it is either possible or desirable to maintain that situation permanently.

[John Brown (no body)]

Re: Electric planes?

"we are currently proving that we don't need...sporting events?"

I'm not seeing the downside there.

[MiguelC]

Re: Electric planes?

we used to fly people from all over Europe for essential face-to-face meetings

everyone, up to c-levels, is now getting that video conferencing serves us as well as in-person meetings ever did and is a lot more economical

if you add the carbon footprint gains, we're in a win-win-win situation

[Cynic_999]

Re: Electric planes?

"

we used to fly people from all over Europe for essential face-to-face meetings

"

I should think that face-to-face meetings comprise the minority of air passengers. Besides, vidoconferencing is a poor substitute for in-person meetings where you get to converse and bond with other attendees during informal breaks, and swap ad-hoc ideas with individuals.

Making a business proposal or selling an idea is far better done in person than by video call. Would you buy so much as a used car that is being sold only via video call?

Tourists make up not only a very large proportion of air passengers, but are also a huge proportion of the economy of many countries. Going back to the time when the most exotic holiday location most people were likely to see was Blackpool would be feasible - but hardly desirable. And it would be disasterous for many countries.

[Yet Another Anonymous coward]

Re: Electric planes?

Would you still fly 100 people to Atlanta so they can sit in the same room and all watch the same CEO give a Powerpoint about leveraging dynamic synergies?

[JibberJabberBadger]

Re: Electric planes?

I have a feeling we may have worked for the same company - ah, I don't miss the days of flying around Europe every week in business class for a two hour internal meeting and the 6 monthly trips to Atlanta for training and meetings that could have easily been done online - massive waste of money.

[Anonymous Coward]

Re: Electric planes?

I used to fly to the US 3-4 times a year for team meetings and design workshops, plus a few trips around Europe to teams and customers. Our team was known as one of the best in the company, solid despite the geographical separation. We always worked well together, our product sold very well.

Now the penny-pinching beancounters are trying to impose video meetings, I haven't been to the US in several years, and am lucky if I get an annual trip to meet the rest of my European team. It sucks, team co-operation is crap, product quality is falling, and I can't wait to leave.

[Nifty]

Re: Electric planes?

Maybe your C-levels haven't yet discovered the idea of an online discussion forum.

[CAPS LOCK]

Absolutely. And just imagine if your MP spent all his/her time in the constituency instead of...

...the Ivy.

[Intractable Potsherd]

Re: Absolutely. And just imagine if your MP spent all his/her time in the constituency instead of...

Well, that depends on your MP, doesn't it? The feckless lump of lard I've currently got seems to be universally disregarded even by the people who voted for her.

[amanfromMars 1]

Re: Electric planes?

Just because something is possible to do for a limited time does not mean that it is either possible or desirable to maintain that situation permanently. .... Cynic_999

I submit it most certainly is possible whenever both highly desired and desirable. What's not to like for a real long time? I mean ...... come now, don't be fooled again.

Does one have to spell out the attractions and temptations that deliver desire for passions to quench and revitalise, in order that you more clearly see the treasures and pleasures before you with an Alien Being in Strange Charge with Universal Key Strokes in/for Fully Virtually Remote Field Operations.

Tell me that really do know what LOVE is? Are you not already told to be aware of Live Operational Virtual Environments?

You realise what it means if you haven't a clue about everything you have just learned there now. It is withheld and being detained and restrained by other forces ..... for something else.

What would you be minded for such other forces to do ..... in Order that Brotherly and Sisterly Orders Always Succeed and Endlessly Prosper and Grow and Evolve ?

Think Big and Bigger Again and Again is Certainly Better in this Case for in the Midsts of Madness are the Acorns and Apples of Genius Tempting their Way Through All Manner and Matter of Engaging Novelty and Passionate Internet Discourse.

[jake]

Re: Electric planes?

Sorry, amfM ... virtual environments don't feed & exercise the dawgs & horses. Nor do they feed the food (hogs, steers, chickens ... ). Nor do they clean up after all the above. The physical world makes the virtual possible, not vice-versa. One can do without the other quite nicely. And oftenusually does.

(Substitute "children" as appropriate if you don't keep livestock.)

[Cuddles]

Re: Electric planes?

"Do you also believe that we are currently proving that we don't need restaurants, pubs or sporting events?"

Well yes. They may be nice to have available, but there's obviously no actual need fo them to exist. If you can't go out for a meal, you can still very easily avoid dying of starvation. And if you're not able to fly from the UK to Australia, you can very easily simply avoid doing so, no matter how much family might be at the other end.

The difference is that pubs have very little environmental impact compared to eating at home, so there's no reason to worry about them opening back up once this lockdown is over. We absolutely have proven that we don't need them, but we want them and have little reason to oppose that want. Planes, on the other hand, do have some serious downsides to their use. And since we've proven that we don't need them anywhere near as much as some people liked to use them, maybe we should think a bit harder about going back to previous levels of use as soon as we can.

[Intractable Potsherd]

Re: Electric planes?

Once again, the eco-miserabilists speak! How dare we have fun? How dare we do things that aren't "necessary"? Don't you know the planet is DYING!!11! 1 eleventy one?

I have no real doubt that the days when we could fly cheaply and relatively efficiently are over - the economic situation is going to provide far less choice, therefore far less competition, as airlines go bust over the next 12 months or so. However, that is going to be accelerated by governments bending to the eco-twats who think that we should all go back to living where we are born and never travelling further than the nearest market town in the name of "duh env-eye-row-mint".

[ICL1900-G3]

Re: Electric planes?

Thank heaven there's another planet just waiting to be used up.

[Intractable Potsherd]

Re: Electric planes?

This one is fine, and will last for ages.

Look, there are some very good reasons for using less, and reusing and recycling what we have. However, in the developed world, we have the safest, healthiest environment in history, and lots of disposable income (on average). Things my parents (born in the 1930s) could not have imagined for the first 40 years of their lives have become commonplace - all of it made possible by the use of fossil fuels. People who want radical green policies want us to move back to pre-industrial levels, without hope of ever getting out, and they want to do it without engaging in proper, democratic, debate.

The developing world will be left forever behind if they adopt green policies, so the "enlightened" developed countries are enforcing it on them, and the complaining that they never make anything of themselves.

When you can talk in terms of the moral correctness of maintaining (for the developed world) and improving (for the developing world) the standard of living through efficient reuse and recycling, we'll have common ground. Talk to me about "only one planet" and I'll not hear a word you are saying.

[Phil O'Sophical]

Re: Electric planes?

And we're currently proving that this is perfectly viable.

No, we're currently proving that it is very, very painful. I won't get to see my family for months, I've had to cancel vacations.

One of my colleagues has been stuck in another country, unable to get home, for 6 weeks.

We need to develop ways to use sustainable fuels, not to just give up on travel.

[Anonymous Coward]

Re: Electric planes?

Regrettably, I don't get to see the mother in law.

[hoola]

Re: Electric planes?

We need to develop ways of living more sustainably or we are seriously stuffed. Currently sustainable fuels are generally plant based and as such are doing huge amounts of damage to the environment. It is the usual our of sight, out of mind, believe the PR bullshit about reduced CO2 and offset.

We have to travel less and we have to stop using resources at the rate we do. When I was at school (a long time ago) a family going on a trip abroad was a major event. Nowdays people are jetting off all over the place for weekends, half terms, AND their main holiday. Air travel is seen as a right and and it must be cheap, not the luxury it actually is.

[Intractable Potsherd]

Re: Electric planes?

See - hoola proves my earlier point perfectly! God forbid that human progress should make that which was expensive affordable by all!!

[rcxb]

Re: Electric planes?

Electric batteries are about fifty times the mass of airline fuel for a given amount of energy.

This is a nonsense comparison. Lithium-Air batteries have a theoretical specific power of 11.4 kW/kg, compared to the theoretical maximum of 11.99 kWh/kg for Jet A-1, so very close.

We don't have those theoretical Lithium-Air batteries, you may say, but that's fine, because we don't have theoretical engines with 100% conversion efficiency for jet fuel, either. And if we did, they wouldn't be zero mass and zero volume, so would negatively affect those numbers. And that's without mentioning that jet fuel needs things like storage tanks, pumps, which also add mass and volume.

The only realistic way to reduce airline fossil fuel consumption at the moment is to fly a lot less.

Actually, a large number of options to reduce fuel consumption exist. Flying wing designs improve performance by 1/3rd, lower air-speeds propelled by turbo-props instead of turbofans are more fuel efficient, just flying slightly at slightly lower throttle (which some airlines have already done) reduces fuel usage at the expense of slightly longer flight times.

[Holtsmark]

Re: Electric planes?

It must also be noted that the efficiency of a combustion based energy conversion has a maximum efficiency of approximately 35% (diesel ICE), whereas an electric machine operates n the high nineties.

Furthermore, an electric drive-train allows numerous advantages with regards to propulsive integration.

Undesired wake interactions can be avoided. Propeller disk loading can be optimized (yielding higher propeller efficiencies at lower speeds). Boundar layer ingestion and propeller / wingtip vortex interactions can be used to further reduse aerodynamic losses.

Electric drive-trains also lend themselves to high redundancy architectures, which increases safety and allows for what would otherwise be deemed to be "risky" strategies like blown wing designs (NASA), further reducing the required wing area and thus drag.

Finally, maintenance- and operational cost can be significantly reduced with an electric drive-train.

These are all things that are being studied intensely, but which will require a number of key technologies to mature before being widel adapted. And meanwhile, the cumulative effect of a couple of percent's worth of annual improvements in efficiencies for conventional aircraft means that there will be a certain amount of catch-up to do as well.

[Anonymous Coward]

Re: Electric planes?

Lithium-Air batteries have a theoretical specific power of 11.4 kW/kg, compared to the theoretical maximum of 11.99 kWh/kg for Jet A-1, so very close.

But they're still there for the whole flight, unlike the liquid fuel that burns off during the journey.

[Graham Dawson]

Re: Electric planes?

And a theoretical specific energy means little if it isn't practically achievable.