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The Celera 500L passenger plane gets hydrogen powertrain
- ufo 4y agoWhat is the deal with its windows?
- V__ 4y agoThe final version will have passenger windows, this is just a prototype.
- ZetaZero 4y agoLooks like the bare minimum windows needed to fly it. Windows create drag. The overall design reduces drag by "59 percent".
- Hextinium 4y agoWould 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.
- tppiotrowski 4y agoI would love this in cars one day. Getting into an unbearable hot car on a summer day would be a thing of the past.
- mlindner 4y agoThat can be handled with pre-cooling your car.
- bityard 4y ago...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 4y agoThe 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 4y agoYes, light travels through glass and not through metal and paint. But if the outside of the car gets hot, the inside will too.
- tppiotrowski 4y agoOn a sunny day, why are the contents of my trunk cooler than the interior of my car?
- elihu 4y agoIt'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?
- numpad0 4y agoI did a napkin math a while back: the standard for 20/20 vision or 1.0 acuity scale equals to 1 arc minute resolution, or 1MOA, or an Euclidean angle of 1/60th degree. A spherical VR image that resolves to 20/20 acuity is as large as (60 x 360, 60 x 180) = (21600, 10800)px before requisite oversampling, and that’s kind of hard. Then of course those fighter guys has/need better visibility than 20/20 which only makes it harder. And by the way modern digital image pipelines buffer and delay transfers, sometimes as much as 200ms, which is absurd considering the CPU runs at literally millions of times better clock frequencies and latencies, but that’s what readily available implementations are. These mean that we are still some time away until such “local remote driving” not just complements but totally replace heat formed and dielectric coated pane of plexiglass. I guess it eventually will beyond upper edge of atmosphere as glasses don’t work well and vision required surpass human eyeballs, i.e. in interstellar settler’s carriages and planetary orbital fighter jets, but for now and for forward windscreen applications, it makes more sense to just put on panes of plain old transparent aluminum.
- ericbarrett 4y agoSome 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 4y agoAirbus A380 has this in first class.
- glowingly 4y agoA 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_Flight_191 https://en.wikipedia.org/wiki/American_Airlines_Flight_191 Looks like it was a cockpit camera, not an external camera.
- _moof 4y agoI was on an Emirates flight that had this.
- tensor 4y agoI 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.
- mlindner 4y agoHow 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.
- tln 4y agoI don't know, I've been on flights with webcams on the nose/tail/belly and found those to be pretty entertaining. And it's available to every passenger, not just the window seats. If an airplane design really leaned in to the webcams, I think it could be fantastic!
- numpad0 4y agoPut aside controversies, I believe the window requirements are for rescuers to scout the cabin in a crash than for occupant entertainment. Else makes no sense to have window shades open during takeoff & landing.
- chipsa 4y agoWindows 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.
- ChadNauseam 4y agoWhy do they create drag? Is it difficult to make them flush with the exterior of the plane?
- mahoro 4y agoI guess the main problem is weight. 6-10 windows might weight ~100 kg, and you'll need more aluminium in the frame because of more complex structure.
- thinkling 4y agoPrototype 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.
- jonplackett 4y agoWas 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 4y agoFully 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
- amscanne 4y agoI 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 4y agoJetliners 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.
- the__alchemist 4y agoWouldn'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 4y agoAlso 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 4y agoPossibly. 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 4y agoNo. 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.
- flybrand 4y agoThe 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 4y agoThey'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 4y agoWhenever 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.
- Maarten88 4y agoExactly what I thought. Laminar airfoils with max thickness far back do very well in the computer but they behave poorly. I would want to see proven that this plane is stable in all conditions. Putting a hydrogen engine in it seems like a distraction.
- kayodelycaon 4y agoMost 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.
- notJim 4y agoIn 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.
- deleted 4y ago[deleted]
- somat 4y agoA 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 https://en.wikipedia.org/wiki/Otto_Celera_500L Also note how the prototype has no windows....
- kayodelycaon 4y agoVery 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 4y ago> 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 4y agoGliders 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."
- BenoitP 4y agoI 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.
- tormeh 4y agoCan'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.
- nomel 4y ago> 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.
- coderenegade 4y agoThis is true, but depending on how you use the hydrogen, you can fly much higher than you would with kerosene. Hydrogen burning jets would fly at around 70-80k feet, not the usual 35k that we're used to. Not to mention, the weight savings mean you cut down on the amount of fuel you need to carry, so the 'blimp' effect is overstated. One third the energy in LH2 gets you around half the distance as an equivalent volume of kerosene, because the volume of hydrogen only weighs one tenth the mass of the kerosene. So getting the same range means you need more volume, but you need less total energy to get you to the same destination because you're lofting less mass.
- tragictrash 4y ago
- walrus01 4y agofor 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.
- _hypx 4y agoNote that a full sized battery pack will also need piping, cooling, cables, etc. So it won't actually reach 255 Wh/kg.
- Robotbeat 4y ago255Wh/kg? That’s not true. About 300Wh/kg has been available for over a decade. The next Gen lithium metal anode and lithium sulfur batteries can do 400-500Wh/kg, up to 650Wh/kg in the lab.
- walrus01 4y agoI'm referring to li ion cylindrical cells in the 18650, 20700 and 21700 formats which are commercially available right now. Which I can buy online in 5 minutes with my visa card from a battery wholesaler. If you can find me the pdf datasheet for one that's above that I'd love to see it! And even better a vendor link. Note I am also referring to something like the actual usable watt hours from a battery before you discharge it below "permanently damaged" state, in the range starting from 100% SOC standard full voltage and manufacturer's do-not-exceed floor voltage. Such as on the NCR18650GA. I don't doubt there are specialty rare "ask us for a price" low volume 300Wh/kg in circulation if you have the right contacts.
- mkeespiet 4y agoSearch 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 https://youtu.be/nrCE9duCej0
- walrus01 4y agoI 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 4y agoAn 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 4y ago>"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 4y agoErr… 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.
- phkahler 4y agoThey'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 4y agoI 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 4y ago[deleted]
- simne 4y agoFor 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.
- elromulous 4y agoI imagine there's some useful information in this comment, but I found it incomprehensible.
- ClumsyPilot 4y agoprecisely
- spaceywilly 4y agoWhy waste time say lot word when few word do trick
- simne 4y agoIf you are illiterate this is opportunity to learn, not reason to burn books.
- rad_gruchalski 4y agoI wonder what happened. This aircraft was designed for a piston engine, RED A03: https://red-aircraft.com/press_release/niche-company-with-a-worldwide-reputation-swr-writes-of-the-amazingability-of-the-a03-engine/ https://red-aircraft.com/press_release/niche-company-with-a-....
- baybal2 4y ago
- collsni 4y agoNow we need more hydrogen vehicles!!
- onphonenow 4y agoOoof. Absolute RED FLAG. These go as follows. --- Hey we have this AMAZING tech (supposedly). But wait, we're not going to commercialize / actually produce it even though if true it'd print money. Look we have this (other) AMAZING tech, we are going to combine these so that's why we aren't showing Amazing Tech #1. And repeat. --- Most get rich books / authors / etc - if they had a way to actually beat for the forex market etc they wouldn't be selling $50/books on how to do it. Same thing here. if they had a massively efficient plane (with a prop - also efficient) they'd actually deliver.
- ngcc_hk 4y agoIs there really any calculation source or even equation of fuel efficiency due to battery is dead weight whilst fuel burn itself. https://github.com/electricitymap/bloom-contrib/issues/271 https://github.com/electricitymap/bloom-contrib/issues/271 This mention spreadsheet with script or pdf. Authority but not that useful for calculation.
- iamtheworstdev 4y agois there an airport anywhere that stocks hydrogen fuel?
- jillesvangurp 4y agoWhy would they? There are no planes to fuel yet.
- dmix 4y agoSome analysis from the 'aviation forums': > But let's say you can climb the thing at 1000FPM and 100KIAS. That takes you an hour (covering roughly 250 nm?) to hit 65,000. If you spend an hour at cruise and then come down at 2000 fpm again covering 150nm ... you've just taken 2:30 block to go 900nm. What market does that make sense in? Might make a great autonomous cargo bird for Fedex. -- > People spending 5 million on an airplane do not care about $180 of fuel difference per flight, and also that is only at altitude. If the climb rate of that airplane is 1,000fpm, which seems optimistic, it would take nearly an hour to get up there. If you are going on a 2 or 3 hour leg, fuel burn could be the same or worse. https://www.beechtalk.com/forums/viewtopic.php?f=49&t=174467&start=15 https://www.beechtalk.com/forums/viewtopic.php?f=49&t=174467... Longer analysis video: https://www.youtube.com/watch?v=E38cc-4TvX8 https://www.youtube.com/watch?v=E38cc-4TvX8
- webreac 4y agoIMHO (almost layman), takoff catapult is the way to go for energy efficiency of aircraft. If you imagine a takeoff around 200KIAS, the conversion of cynetic energy in potential energy gives you a big part of the climb. The spared energy would increase the flight range.
- joeblow21 4y ago
- seu 4y agoAn amazing technology, optimizing the thing we need the least right now: rich people's private jets. We need to fly as little as possible, not to incentivize it even more. 80% less fuel consumption? Expect people flying 5 times more, and feeling like they are doing a favor to the environment. Jevons Paradox.
- rsync 4y agoI don’t understand your comment… If, indeed, this can be made to work with a zero emission hydrogen power source, why would we seek to limit that air travel the same way we might seek to limit fossil fuel based planes ? Are you suggesting that air travel - of any kind - is negative?
- jnsaff2 4y agoSure, once world emissions are zero, this could be zero emission. Before it obviously comes at the expense of something else.
- allisdust 4y agoYes. The core concept of progressive views is 'pain and sacrifice'. It doesn't matter who but someone should always be making some personal sacrifices for the whole to be satisfied. Some times it is plastic straws by common people and some other times it is billionaires's hydrogen jets.
- trhway 4y ago>Running on an efficient 550-horsepower combustion engine, Otto claims this thing will fly six passengers up to 4,500 nautical miles (8,334 km) at cruise speeds over 460 mph (740 km/h) That is the top warbirds' speed at 1/4th power and double range. Basically a top speed for a reasonably powered propeller aircraft. Sounds like we have a winner here. I wonder if chasing hydrogen fuel cell will add a lot of costs and risks in development and various issues for users like it can be expected with a new technology. I'm all for electric, yet i think it may make sense to separate development/products - one is extremely efficient and fast plane with already great aircraft diesel, and another - the same plane (or may be adjusted as needed) with hydrogen.