[HN Gopher] The Celera 500L passenger plane gets hydrogen powert...
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The Celera 500L passenger plane gets hydrogen powertrain
Author : clouddrover
Score : 79 points
Date : 2022-06-16 11:15 UTC (1 days ago)
(HTM) web link (newatlas.com)
(TXT) w3m dump (newatlas.com)
| phkahler wrote:
| They're doing something that's a red flag IMHO by talking about a
| fuel cell version. If you've got a great idea - and 80 precent
| less fuel consumption should qualify - then bring it to market.
| Every additional "revolutionary" concept you add increases the
| risk of a new product never materializing. Next up, an all new
| material and manufacturing process... 3D printed crypto
| nanotube/metal composite!
| cjbgkagh wrote:
| I assume they're just taking free money from a third party to
| subsidize their main development. If the fuel cell partnership
| works then great otherwise no big deal.
| [deleted]
| kayodelycaon wrote:
| Most efficient small-scale prototype of a passenger plane...
| title is way overselling the article.
|
| Edit: All of the photos are of the smaller prototype... and I
| missed the text saying they had a full-scale one. Oops.
| [deleted]
| notJim wrote:
| In the article, it says the it's a full-scale prototype. Still
| agree the title is overstating it, especially since they
| explicitly say the design cannot be used for an airliner.
| flybrand wrote:
| The claims made by Celera have always been aggressive - and I
| hope they're real. Why add more claims? Why not just deliver on
| what they currently offer?
|
| This seems like a red flag and possibly indicates shenanigans.
| mometsi wrote:
| They've optimized for cabin volume and all their claims are
| weirdly crafted to take advantage of that design choice.
|
| For passengers who expect a flight with 4 first class-type
| seats, their competition isn't a minivan with wings like the
| beechcraft bonanza, it's a learjet with half the seats removed.
| kashkhan wrote:
| Whenever a company pivots to another tech without publicly
| proving the original tech, i get the heeby jeebies.
|
| If laminar flow tech worked as they claimed, you wouldn't need
| hydrogen to be a market success.
| ufo wrote:
| What is the deal with its windows?
| ZetaZero wrote:
| Looks like the bare minimum windows needed to fly it. Windows
| create drag. The overall design reduces drag by "59 percent".
| ChadNauseam wrote:
| Why do they create drag? Is it difficult to make them flush
| with the exterior of the plane?
| chipsa wrote:
| Windows themselves don't create drag, it's the interruption
| of the surface that creates drag. If they do a very good job
| of getting the windows put in, it shouldn't be an issue. The
| bigger reason is: it's a prototype, so it's easier not to cut
| the windows out and fill them with glass.
| Hextinium wrote:
| Would be interesting to make "virtual windows" where you take
| a camera on the hull and just stream its feed to like the in-
| flight entertainment system or a wall mounted monitor.
| mlindner wrote:
| How about no? A camera doesn't give you the same view as a
| window does. You can't move around to get different angles.
| Not to mention the pixel resolution of in-flight
| entertainment is nowhere near what you get with your eyes.
| Looking out the window at the sights is one of the few
| great things about flying.
| tppiotrowski wrote:
| I would love this in cars one day. Getting into an
| unbearable hot car on a summer day would be a thing of the
| past.
| elihu wrote:
| It's kind of a weird idea to get used to, but I think
| windowless cars could be pretty cool. Maybe the driver
| puts on a VR helmet and can see everything. (Obviously
| the technology would have to be extremely reliable.)
|
| It solves a bunch of problems: it gets rid of all the
| trade-offs between structural integrity and visibility.
| It reduces costs and makes manufacturing easier. The
| driver could be anywhere, even in the back seat if that
| makes sense for some reason.
|
| This seems like it would be extra useful for military
| vehicles. I wonder if you were to redesign something like
| the A-10 or F-16 from scratch and you could put the pilot
| anywhere you want because visibility isn't an issue,
| would you come up with the same design or would the
| cockpit end up somewhere strange, like in the back of the
| plane?
| mlindner wrote:
| That can be handled with pre-cooling your car.
| bityard wrote:
| ...a car without windows would get hotter than one
| without because windows are at least somewhat reflective
| (depending on the angle of the sun) and because they can
| be left cracked open to let the heat escape.
| happyopossum wrote:
| The first half of your supposition is dead wrong, but the
| second half is correct. Opaque materials will always
| transmit less solar energy than transparent materials.
| The most effective insulated multi-pane windows available
| for homes today are still less efficient than a wall.
| bityard wrote:
| Yes, light travels through glass and not through metal
| and paint.
|
| But if the outside of the car gets hot, the inside will
| too.
| ericbarrett wrote:
| Some passenger jets have had this for a while, giving you
| various views from the seatback screen. Not sure which
| airlines or jets but I've definitely heard of it.
| metadat wrote:
| Airbus A380 has this in first class.
| _moof wrote:
| I was on an Emirates flight that had this.
| glowingly wrote:
| A similar camera was present on the old DC-10. AFAIK, it
| was removed after an pretty big crash in Chicago. Nothing
| to do with forthrightness, iirc (outside of the usual
| flying coffin perception of the DC-10).
|
| EDIT: https://en.wikipedia.org/wiki/American_Airlines_Fli
| ght_191
|
| Looks like it was a cockpit camera, not an external
| camera.
| tensor wrote:
| I absolutely loved the few times I was in a plane that
| had a forward and downward facing camera that you could
| watch on the screen. So great to just watch it for hours.
| Windows are nice but in most transatlantic flights they
| are all closed the majority of the trip so that people
| can sleep.
| V__ wrote:
| The final version will have passenger windows, this is just a
| prototype.
| walrus01 wrote:
| for comparison between battery and energy density:
|
| typical lipo as used in a short flight endurance hobby quadcopter
| (5-7" prop size) is 155Wh/kg
|
| the best lithium ion cylindrical cells are around 255Wh/kg right
| now. quite a bit more limited in instantaneous amperage draw per
| cell than high C rate lipo.
|
| hydrogen fuel cell tank+PEM+piping+DC apparatus for large
| octocopters comes in somewhere around 1500Wh/kg
|
| There's a south korean company that recently hovered a large
| octocopter with hydrogen power source for 10.5 hours. Same system
| with lithium ion battery power would be approximately a 1 hour
| endurance.
|
| note that 1500Wh/kg is considerably less than the energy density
| of jet-a or diesel or ordinary 87/89 octane petrol, BUT, you have
| to account for 50% of it being lost to waste heat in an internal
| combustion engine, and the weight of the engine and drivetrain.
| or weight of jet turbine+generator vs hydrogen tank + fuel cell
| PEM apparatus.
| BenoitP wrote:
| I don't believe regular planes to ever run on hydrogen and be
| commercially viable. Hydrogen is not very dense, even in liquid
| form (to be compared with the volume already taken by kerosene on
| a plane). And requires very strong -and thick- container walls.
|
| However with dwindling fuel supplies, I'm pretty positive we'll
| see the return of glorious, massive blimps. Powered by a fraction
| of the hydrogen it uses to float in the air, savvy meteorology,
| and thin solar panels.
| kurthr wrote:
| Not really, it's more likely to be stored at low temperature to
| avoid embrittlement. Liquid Hydrogen has an energy density of
| approximately 120 MJ/kg, almost three times more than diesel or
| gasoline. Even with the cryogenic storage and reheating
| equipment it has comparable power to weight ignoring electrical
| motor efficiency advantages. Comparable flight hours do take up
| 2-3x more volume than diesel (including pumps and fuel cells),
| but at larger sizes (e.g. 737 and larger) most commercial
| flight distances are limited by weight rather than volume.
|
| A lot of things come down to scale. Small drones can run
| reasonable distances on LiPo, which scales very badly to larger
| vehicles.
| kristopolous wrote:
| Right. The strongest evidence is commercial planes will be
| exclusively hydrogen powered. Airbus is working on one right
| now https://www.airbus.com/en/innovation/zero-
| emission/hydrogen/... (I think 2035 is way too long - it
| needs to be done 10 years ago)
|
| What more there will be hydrogen fuel plants onsite at the
| airports
|
| Additionally you'll see hydrogen in similar large systems
| such as rail and earth moving equipment.
|
| Honestly the only question I have in the large vehicle
| systems is cargo ships. There's plenty of space and benefit
| to large solar wings expanding the vessel surface area that
| can fold up when necessary
|
| If you see the efficiency gains and cost reduction in
| commercial grade PV continue, it's going to be unit cost
| economically superior fairly soon.
|
| Alternatively there could be some mystery device that can get
| a net energy gain by processing sea water to hydrogen fuel.
| This doesn't look physically impossible but I haven't heard
| of any serious efforts to do so yet and personally I'd need a
| lot of convincing to be assured it wouldn't just be doing a
| new flavor of ocean polluting
| rbanffy wrote:
| > Liquid Hydrogen has an energy density of approximately 120
| MJ/kg
|
| 8 MJ/liter for liquid hydrogen vs. 32 MJ/liter for gasoline
|
| Size matters
| nix23 wrote:
| >I'm pretty positive we'll see the return of glorious, massive
| blimps
|
| Na thanks i take the train ;) But for good's i could image
| that.
| clouddrover wrote:
| Air Nostrum has ordered some airships:
|
| https://edition.cnn.com/travel/article/airlander-10-air-nost...
| tormeh wrote:
| Can't the low density be taken advantage of, producing aircraft
| with blimp-ish characteristics? Not sure how practical that
| is...
|
| And given how big % of fuel is needed for ascending to cruise
| height, I'd imagine you could have a decent % of the fuel in
| take-off tanks with thin walls, since those tanks only need to
| contain the fuel for less than 10 minutes anyway.
|
| I could imagine future planes using hydrogen for take-off and
| batteries for cruising.
| tragictrash wrote:
| No.
| nomel wrote:
| > producing aircraft with blimp-ish characteristics
|
| Drag nearly directly proportional to the cross section of the
| craft. Something blimp like would be necessarily slow, to
| stay efficient.
| simne wrote:
| For plane engineering aware person, all ok.
|
| - Commercial planes begin at about 50-60 seats, less are non-
| viable on median market (90%), but could be unavoidable or very
| competitive in some niches, like tractor-planes for swamps.
|
| Normal commercial size - 100 seats.
|
| For air-dynamics, 3 times capacity enlarge (from 6 to 18)
| typically possible, but more changes too much.
|
| And 3 times capacity in avia measured non linear, but with famous
| square-cube rule, which mean, change size will increase mass as
| square, but capacity as cube, so to got 3x capacity, need 1.443
| increase of size (1.442^3=3.0046853). This is possible in most
| cases.
| mkeespiet wrote:
| Search for "Bernard van Dijk" on LinkedIn. He is a professor on
| an Aviation University. He has a very solid story about why
| hydrogen will never work in airplanes. I'm addition, a well
| explained video about it: https://youtu.be/nrCE9duCej0
| walrus01 wrote:
| I wouldn't say never, but based on the tankage requirements and
| tank structural needs for high pressures, it'll be limited to
| short range regional craft only.
|
| There is still a lot of market in the size of things like the
| Q400 flown by Alaska Air. Like a Seattle to Montana flight.
| lifeisstillgood wrote:
| An interesting video - but I am unconvinced this is "hydrogen
| can't work" - just the current approach won't work.
|
| The point seems to be (watch the video) that the fuel is
| currently stored in wings of aircraft, which in layman's terms
| means the wings bend up carrying the weight of the fuselage,
| but the weight of the fuel is in the wings meaning fuel weight
| does not contribute to wing bend
|
| Current hydrogen fuel power trains put the hydrogen into the
| fuselage in big tanks. This means the fuel weight now does
| count to wing bending and so fundamentally you can either take
| off without passengers or you can have your wings snap.
|
| The answer seems to be put the hydrogen fuel in the wings. I
| could not find the argument against that. I suspect there is a
| lot more in the weeds in the industry
| nickff wrote:
| > _" The answer seems to be put the hydrogen fuel in the
| wings. I could not find the argument against that. I suspect
| there is a lot more in the weeds in the industry "_
|
| This is impractical with current technology. The insulation
| for liquid hydrogen in wings would be impractically thick and
| heavy. The structure for pressure vessels for gas in wings
| would also be impractical.
| doctor_eval wrote:
| Err... not all the fuel goes in the wings, and not all planes
| put their fuel in the wings.
|
| This argument makes no sense to me.
| nickff wrote:
| I believe that all modern commercial aircraft, and many
| smaller ones store substantial proportions of their fuel in
| the wings.
| mmaurizi wrote:
| Seems like you need a flying wing design so you can have
| gigantic wings to put your giant tanks (and also passengers)
| in. Maybe this
| https://www.nbcnews.com/mach/science/futuristic-flying-v-
| air... ?
| dragonwriter wrote:
| The reason hydrogen in the wings doesn't work is because
| wings are thin and hydrogen tanks need thick walls. Also a
| lot more volume (hydrogen is not super mass inefficient as a
| fuel, but is super volume inefficient.)
| somat wrote:
| A bold claim, perhaps they have done it but I have my doubts that
| such a large efficiency gain is left in aeronautical engineering.
|
| And also because any time I see "% reduction" that is a bit of a
| red flag. Whats the math on this one?
|
| (existing 6 passenger plane drag[cessna citation?] - (existing 6
| passanger plane drag * 0.59) = celera 500 drag)?
|
| the wikipedia article goes into a bit of detail on some of their
| more dubious claims.
|
| https://en.wikipedia.org/wiki/Otto_Celera_500L
|
| Also note how the prototype has no windows....
| kayodelycaon wrote:
| Very amusing wikipedia article. The only things that aren't
| speculative are when they started, how much funding they
| raised, and how many flights their prototype has had.
| Tuna-Fish wrote:
| > A bold claim, perhaps they have done it but I have my doubts
| that such a large efficiency gain is left in aeronautical
| engineering.
|
| It is a laminar flow design. It's been known for a long time
| that you can push drag down a lot below the state of the art in
| commerical aviation that way, and it's been used in a lot of
| gliders, but it doesn't come for free.
|
| Most importantly: The shape of the aircraft is almost entirely
| determined by physics, not your wishes, which typically makes
| it quite inconvenient to build and use. Maintaining the high
| performance depends on keeping the skin of the aircraft very
| clean and smooth -- even collecting a few too many bugs can
| cause a lot of problems.
| sandworm101 wrote:
| Gliders have a wing cord of maybe a foot or two. The body of
| this thing is like 30 feet long. Maintaining laminar flow
| across such a surface is mostly impossible. Bugs and
| scratches are bad, but at that size tiny paint defects would
| be an issue.
|
| "This is your pilot speaking. It looks like we have some bird
| dirt stuck to us. We therefore must cut our journey short."
| the__alchemist wrote:
| Wouldn't a flying wing design be more efficient? I'm suspicious
| this comes down to engineering a big-enough pressure vessel into
| the wing design.
| mateo1 wrote:
| Also good luck landing this thing with strong crosswinds. Or
| god forbid rupture the pressure vessel with a hard landing...
| It's an interesting concept but looks very impractical.
| darksaints wrote:
| Possibly. Though functionally this isn't much different from a
| flying wing, as the fuselage is a lifting body. It's basically
| like a large capacity powered glider.
| kayodelycaon wrote:
| No. Flying wings do not allow for efficient internal layout of
| passenger seats, cargo areas, and engines. You're better off
| designing something with minimal wing drag and a body that
| provides additional lift.
| thinkling wrote:
| Prototype can hold 6 passengers. The design can scale up to 19,
| but "the low-drag laminar flow model relies on a width-to-length
| ratio that'd be impractical in a bigger bird" so it won't work
| for airline use.
| [deleted]
| rbanffy wrote:
| > "the low-drag laminar flow model relies on a width-to-length
| ratio that'd be impractical in a bigger bird" so it won't work
| for airline use.
|
| We can always reimagine airports as well.
| jonplackett wrote:
| Was wondering about this - im just not that impressed about
| anyone making personal jets more efficient. Those things
| shouldn't be in the sky in the first place.
| nawgz wrote:
| Fully agreed. Personal aviation is ludicrously inefficient
| and still often remains outside of meaningful regulation in
| key ways like using leaded fuels. Poisoning the globe and
| locales for one person's convenience should always be
| questioned as a sign of inequality too far gone
| S201 wrote:
| Let's not be so dramatic as to say that the general
| aviation fleet is single handedly responsible for poisoning
| the world with lead.
|
| When leaded car gas was still in use it resulted in 4-5
| million tons of lead emissions per year.[1]
|
| The use of leaded aviation fuel contributes 500 tons per
| year according to the EPA[2]. Compared to 5,000,000 tons
| for cars historically.
|
| Of course, any lead is not good and we should be shooting
| for zero. Which is the goal of the unleaded G100UL aviation
| fuel. But let's not try to say that personal aviation is
| evil when it's contributing a fraction of a percent of lead
| contamination. Frankly, we have bigger pollution problems
| to worry about than a very small amount of lead emissions
| from an ever shrinking fleet of piston powered aircraft.
|
| Mind you that general aviation is more than rich people
| flying around in their planes. It's medical flights, it's
| training future airline pilots, it's aerial surveying, and
| many more critical tasks for society.
|
| 1. https://grist.org/regulation/leaded-gasoline-lead-
| poisoning-...
|
| 2. http://www.reidhillview.com/EPA_GA_Lead_2002.pdf
| simne wrote:
| I'm agree with you about lead is bad, but only oldest
| designs of aircraft engines depend on lead (they use it
| as lubricant for valves, as it deposits on surfaces when
| gas evaporate).
|
| Because of this, leaded gas still produced in commercial
| volumes.
|
| Modern aircraft engines could work on unleaded gas, and
| especially Celera use aircraft diesel engine, working on
| basically aviation kerosene (with tiny addition of
| lubricants for diesel equipment).
|
| BTW diesel add about 30% of Celera range.
| nawgz wrote:
| https://paloaltoonline.com/news/2021/08/06/new-study-
| finds-l...
|
| I in no way imply aviation is the greatest poison emitted
| by humanity; it is one of the most selfish emissions by
| any standard. It is not that leased fuels support
| meaningful industry as suggested, nor is it as if there
| are not alternatives. Instead, the FAA and pilots of
| piston driven planes have simply decided lead poisoning
| is a justifiable price to pay for people living near an
| airport in exchange for individuals getting to fly their
| quarter million+ $ aircraft.
|
| Everything you suggest it is useful for could be
| performed with the already proven and no longer new
| unleaded alternative. Defending this practice is asinine.
| sokoloff wrote:
| Jets [and turboprops] don't use leaded fuel. Many of the
| small, piston-engined airplanes do, but because current FAA
| regulation forces them to, not because of a lack of
| regulation.
| S201 wrote:
| It hasn't been a regulation issue from the FAA that
| piston engines must use leaded fuel for some reason but
| rather there hasn't been a viable unleaded aviation fuel
| that worked with all piston engines.
|
| This is about to change though with G100UL finally being
| approved. https://gami.com/g100ul/g100ul.php.
| nawgz wrote:
| I would, as I did, call regulations forcing stupidity as
| a lack of meaningful regulation; but I take your point.
| It is even a problem of negative regulation.
|
| Small jets do indeed use jet fuel but have a terrible
| efficiency proposition when ran at even 50% capacity,
| which is not the standard use case.
| DakotaR wrote:
| And some engines are rated to run automotive gas, but
| it's just not available at smaller airports.
| sokoloff wrote:
| Most of those are only rated to run on E0 (ethanol-free)
| gasoline, which is also hard to find outside the airport
| fence in most places.
| grogenaut wrote:
| I was actually surprised when I looked how many places
| carry e0. There were several near me in Seattle.
| https://www.pure-gas.org/
| amscanne wrote:
| I imagine that at capacity, they can just as efficient as
| larger jets (if not more efficient). There may be a sweet
| spot in terms of efficiency that can be achieved that is
| smaller than what we've got now. We've already seen jumbo
| jets fall out of favor, and e.g. this can be seen in the
| sales of the A380 and 787 (launched around the same big,
| with A380 going big, and 787 going efficient and mid-sized
| with about 10x the sales). I imagine that planes would get
| smaller still, but the reason they don't is that even with
| high oil prices, human costs still tend to dominate the
| cost of a flight (two pilots, cabin crew). It's not so hard
| to imagine that with more automation it will become viable
| to have much smaller, more frequent routes that are both
| more economically and environmentally efficient.
| nawgz wrote:
| Jetliners have an industry average 51mpg per passenger.
| Private learjets pull, at capacity, 28mpg per passenger.
| I'll let you decide which one of these flies around more
| often at lower percentages of capacity.
| nickff wrote:
| Learjet was a brand name (used to be an independent
| company founded by Bill Lear), which is no longer active
| (after having been acquired and subsequently
| discontinued). The more generic terms are 'general
| aviation' and 'business aviation'; most small jets are
| 'business jets'.
| nawgz wrote:
| I am citing specific statistics for a specific and
| popular private jet, as these things are not well
| analyzed for not surprising reasons. Feel free to prove
| the point with statistics, semantics are definitely an
| aside to the point at hand
| nickff wrote:
| You're comparing obsolete small jets to a much newer
| fleet of commercial passenger aircraft. While business
| jets do tend to be older, your choice is rather extreme,
| and introduces a huge bias. This website has some
| interesting examples of more modern aircraft in a few
| categories: https://www.flyingmag.com/the-most-fuel-
| efficient-aircraft-i...
| nawgz wrote:
| A bunch of 4mpg 7-8 seaters align perfectly with my
| criticism of private jets. Actually, I don't really
| understand what leads you to think there is any pressure
| in this space for fuel efficient development. In the
| space of jetliners, the airlines optimize for cost, of
| which fuel is a primary driver.
|
| While it is cool local planes pull 25mpg, they spew lead
| on their local communities.
|
| I don't think humanity can put the cat of air travel back
| in the bag, and if I understand correctly the SUV market
| is actually driving as much CO2 emissions as the entirety
| of aviation; I still don't see why individuals should be
| privileged to do such damage of poison and inefficiency
| for their pleasure. It is pleasing to others to imagine a
| long lived humanity on a globe hosting life as we know
| it, after all.
| simne wrote:
| For plane engineering aware person, all ok.
|
| - Commercial planes begin at about 50-60 seats, less are non-
| viable.
|
| Normal commercial size - 100 seats.
|
| For air-dynamics, 3 times capacity enlarge (from 6 to 18)
| typically possible, but more changes too much.
|
| And 3 times capacity in avia measured non linear, but with
| famous square-cube rule, which mean, change size will increase
| mass as square, but capacity as cube, so to got 3x capacity,
| need 1.443 increase of size (1.442^3=3.0046853).
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