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Elongated sphereoid overlay for aircraft

Punch air and move smoothly through it
  [vote for,

An elongated spheroid has a better aerodynamic profile than a typical aircraft's tubular form. Tubes are used because they're easier to build and modify, but aircraft shaped like elongated spheroid aircraft have much better performance.

The idea is a lightweight , semi-rigid balloon to be used as an overlay for the fuselage. The front and frame would be made of aluminum, but largely it would be made of whatever material (steel?) would be the best weight-strength(shear and tear strength, right?) ratio. It would be inflated with air to maintain shape. Thusly, the airplane would be given much better performance for a relatively small cost in weight, and still have all the important stuff unchanged.

Voice, Jan 08 2021

Some interesting shapes https://www.bbc.com...l-planes-take-shape
I think the first picture looks like your idea, though likely not built the way you're describing [kdf, Jan 08 2021]

birds flying in a formation save 20-30% of their energy https://www.science...rds-fly-v-formation
[beanangel, Jan 09 2021]

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       // It would be inflated with air to maintain shape //   

       With an aircraft traveling at 500KIAS, that's going to be a formidable pressure.   

       The wings (and possibly engines) still need to project beyond the enclosure. Longer wings = more all-up takeoff weight, apart from the change in drag.   

       The empennage needs to project into clear airflow beyond the enclosure. Bigger empennage = again, heavier plane.   

       The tubular form is chosen because of the requirement for pressurization; the "ring" better resists the expansive force of the air in the cabin.   

       // a relatively small cost in weight //   

       Maybe not for the enclosure, but you still have to compress air to fill it, and there are weight penalties elsewhere.
8th of 7, Jan 08 2021

       Everything 8th said, plus the fact that your idea presumes (incorrectly) that aircraft fuselages are the same cross section from nose to tail. For the most part they're already rounded or tapered at the front and back, and vary in diameter along their length.   

       And the ones that are *mostly* the same diameter between the nose and the tail are designed that way - as the best choice for the aircraft's purpose.
kdf, Jan 08 2021

       The delta-planform "flying wing" is almost, but not quite, an implementation of the idea, and flying-wing aircraft are Baked and WKTE ...
8th of 7, Jan 08 2021

       Like streamlining a blob of putty (or perhaps dry ice!) with water an analog/ analog computing approach might find optimal aerodynamic spheroids quickly. Camphor and C6F14 are both solids that sublime above STP; 3D printing say a thousand starter subliming-material shapes, and then putting them in an actual mini-windtunnel could find how they streamline.   

       Then among the top 11, you could use those as seeds at a genetic algorithm that simulates physics.   

       You could also continue the wind tunnel tests on the most efficient-thus-far spheroids, adding things like tails/blob flares so they have horizontal stability, or elongating them somewhat so they can accommodate more passengers or cargo.   

       Using materials that sublime in wind tunnels could be new; notably the temperature of the wind tunnel can be adjusted to cause the subliming blobs to wear away faster or slower.   

       Getting extravagant there are $1.80 alibaba electric levitating top toys; making an array of those, and putting magnets inside the streamlining subliming blobs could avoid wire suspension. Also, the magnetic top electronics could do things like vibrate the blobs (imitation turbulence; local reynolds numbers).   

       Noting C6F14 sublimes, there might be whole family of branched C3-7F(n) that sublimate different or better. Similarly camphor molecular variants are possible.   

       -->Stuff in front of an airplane, or a submarine/boat:   

       Perhaps dronelike shapes fly just ahead of an airplane to laminarize the flow behind them, making it easier for the big airplane behind them, improving fuel efficiency. I remember thinking it could work with automotive vehicles, trucks, and maybe improve the energy efficiency of big ships like container ships as well.   

       Things to suggest this could work:   

       I read V-flocks of birds are sharing aerodynamic efficiency with each other. The internet says it makes them save "20-30%" of their energy this way.[link]   

       I also head about some shape of Russian submarine that used high speed cavitation to make a bubble it traveled in so it could go really really fast. So, at some further levels this fluid-of-travel prep thing works.   

       Finding optimal fluid-dynamic leader shapes and their complementary craft shapes sounds like a great use for genetic algorithms and neural networks.   

       I like the idea of hydrodynamic leader shapes, and at shapes other than V, although suggested by bird's V-flocking, that make international container shipping even cheaper from saving fuel. 20-30% would be great and there may be ways to do better. Power is easy as they are just connected (like a podracer) to the big container ship's energy supply. This might also work with superfast motor boats.   

       Doing better than birds: Notably, birds V-flock, and it looks 2D planar. Humans can design things with computers and make aerocooperative or hydrocooperative fluid-conditioning pre shapes at 3D shapes in arrays. That is, rather than a V-flock, it might be like a 3D splayed condom/ogive that assists hydrodynamics below the surface as well as at the surface. Or this could assist to make better, more efficient aerodynamics at plural 3D non-V placement of preflyers.   

       Also doing better than birds: In a V, birds seem to have one ahead-bird as a neighbor, rather than say one on each side, or hey, why not go polygonal and have 4,6,8 preflyers like a tube preceding them to smooth the air? The really encouraging thing about going 3D/plural with this is that it might permit exceeding the birds 30% "just one airgrooming neighbor on one side" 2D energy efficiency increase.   

       A kind of mild 2022 thing might be a sailboat/yacht with photovoltaics that power v-flock-ish hydrodynamic pre-prep (with, it must be said electric motors) leading the sailboat or yacht. Similarly V flocking drones on a photovoltaic covered glider might work.   

       The flying machine could be a blob, or [Voice]' spheroid that is actually a sparse grating, like the louvres on say a household fan cover, or, better a super porous open cell foam. If you put a quadcopter/octocopter drone in the middle of the spherical shell, it can still fly (and lift the shell) because the holes are big enough to allow airflow.   

       Between several mm holes and say, 99.9% "breathable" thin shell foam (aerogel?) you get the a continuum of "air movement transparency" <--> actually being some sort of aerodynamic/airfoil effect with the shell having an aerodynamic surface. Perhaps between those two things there is an optimum of VTOL/stationary hover and streamlined forward travel spheroid aerodynamic efficiency.   

       So: it saves fuel like [Voice]' inflatable blob; it VTOL maneuvers like a drone, and niftily, looks like a UFO until people are used to it.   

       As a toy, Nerf (open cell foam shell) drone can collide with anything harmlessly and still fly.
beanangel, Jan 09 2021

       Actually [Voice]' "Punch air and move smoothly through it" Might work even better at hydrodynamic applications like improving the fuel efficiency of big container ships. Could planar jets of water on the sides and back of ships separate and deflect the turbulent (drag) layer, replacing it with a laminar layer? Pumping water is pretty easy.   

       Also, as a nifty and aesthetically interesting aside, I read they use coherent (or at least collimated) water in the fountains at Disneyland. The water passes through a lot of parallel tubes, "calms down", reunites as laminar flow and goes up and out the fountain spouts, making them look like perfect tall cylinders of water many meters high. They mentioned some number about how much taller their fountains could be, and I imagine it might have even had light-piping benefits for lightshow/fountains.   

       So, the container ships could likely use collimated water to make the planes of hydrodynamic laminar flow that increase fuel efficiency.   

       Punching holes in the air in front of an airplane is new to me, [Voice], but I could see how it could work. As a variation, if the humidity is high (flying through clouds) something as primitive as cofocalized computer controlled ultrasound could increase efficiency by sculpting/shaping/diverting or even condensing moist air... Seems extreme.   

       One possible way of punching into air to change airflow could be lasers or magnetohydrodynamic amounts of RF. If it is possible to broadcast a little tiny 5% better mileage wingtip winglet, then perhaps it is possible to make a "Sculpted Air" Ogive/laminar condom in front of the plane.
beanangel, Jan 09 2021


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