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Aerospace Can a plane without wings fly?

  1. Sep 16, 2014 #1
    In a large passenger plane wings used to create lifting force. But in order to create lifting force, body of a plane could be used as well. In order to create as much as possible lifting force you need to have as much as possible difference between upper and down streams of air. In order to slow down air under plane body bottom some straps under bottom could be made. You could even make this straps with regulated angle of air resistance. What is problem with it?
     
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  3. Sep 16, 2014 #2

    NTW

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    Already invented... Look in the internet for 'lifting body'...
     
  4. Sep 16, 2014 #3

    boneh3ad

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    Well for starters, by putting some kind of drag-inducing features on the bottom of the body, you will certainly slow down the air, but not in the way you are thinking. The viscous drag involved is dissipative, so while you will be slowing down the air, it won't give you nearly the pressure rise you are hoping to create because it will also be removing energy from the flow and therefore the total pressure would decrease, removing a substantial portion of the available energy that would otherwise go toward increasing static pressure, which is the relevant quantity for lift. In essence, it would be remarkably inefficient to achieve lift this way. There are, as previously mentioned, lifting bodies already in use, but the body itself is shaped such that it generates enough lift to glide.
     
  5. Sep 16, 2014 #4
    Those are designed to work at supersonic speeds only, and they are claimed not always working well. They cannot go in the sky from the airstrip, instead they should be dropped from supersonic plane.
     
  6. Sep 16, 2014 #5

    boneh3ad

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    That should tell you something, though. These bodies are specifically designed to generate lift, yet they are inefficient at low speeds and require quite a bit of thrust to get sufficient lift. Compare that to your proposal and the best you can do is essentially these sorts of lifting body shapes and your idea would fall somewhere under that in terms of efficiency and feasibility. Ultimately, it's all about thrust, weight and angle of attack. Given a sufficient thrust and angle of attack, you could make a refrigerator fly, just not very efficiently. The same is true of simply removing the wings from a plane. It also wouldn't be very stable.
     
  7. Sep 16, 2014 #6

    rcgldr

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    The M2-F2 (the glider version of the later rocket powered M2-F3) could glide and land reasonably well at sub-sonic speeds:

    m2f2_1.jpg
     
  8. Sep 16, 2014 #7
    What if we direct jet streams from plane engines not horizontally but under certain angle? Could it help to increase lift? The total surface of large passenger plane body is large enough, it should generate plenty of lift if designed to do so, I think. Why it cannot be regarded as a narrow and long wing? What methods could be used to increase it lift a lot without sacrificing efficiency?
    At the beginning of this video you could see how this small plane is dropped from a large one.
    And it's landing with frightening speed.
     
    Last edited by a moderator: Sep 25, 2014
  9. Sep 16, 2014 #8

    boneh3ad

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    Sure, thrust vectoring could increase "lift" in that it is an additional upward force on the body. If course, it would then decrease the upward force as a result of the forward motion of the plane slightly, so whether it would result in a net increase would depend on geometry. For example, the V-22 Osprey is an extreme example of this when it turns to helicopter mode for VTOL operations. As the thrust is vectored more and more vertically, there is less generated by the wings.

    The surface area of the fuselage of a passenger plane is plenty to generate lift but it would require a large amount of thrust to do so and a higher angle of attack than would be otherwise desired. It would also not be very aerodynamically stable given that it is just a cylindrical tube. Like I said, you could make a refrigerator fly if you had enough thrust and angle on it.

    Regarding changing it to be suitably designed to generate lift, the suitable design is the lifting body previously mentioned. The aren't optimal for the type of flight profiles common on passenger jets, but of course, the existing designs for planes are not the optimal shape, either. One of the best solutions, aerodynamically speaking, is the blended wing body, for example the X-48.

    What is your goal for this idea? What motivates removing the wings?
     
  10. Sep 16, 2014 #9
    Increase in maneuverability, portability and reliability.
     
  11. Sep 16, 2014 #10

    boneh3ad

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    I'm not sure you would gain many of those by removing the wings, to be honest. They are already portable, after all, they fly anywhere. There is no reason to put them on a flatbed or anything. I don't see how reliability would be affected. Planes are already some of the most reliable machines we make. You could certainly improve maneuverability, but why would you need to do so? Current airliners are already maneuverable enough and making them more so would simply screw with the passengers. Fighter jets are already maneuverable enough that they are pushing the limits of what a human body can handle.
     
  12. Sep 17, 2014 #11

    rcgldr

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    It was a re-entry prototype, so it needed to be able to handle very high speeds. My guess is the landing speed was probably a bit less than the ~220 mph landing speed of the Space Shuttle, but being a small aircraft, it looks very fast.
     
    Last edited by a moderator: Sep 25, 2014
  13. Sep 17, 2014 #12
    The airships have no large wings. Are they unstable?

    450px-Zeppellin_NT_amk.JPG

    There would be no chances that wing will simply fall out as it sometimes happens, a plane will not crush in other plane or building on airstrip or in the air and not scratch anything with a wing. Imagine a plane on airstrip without wings. It would have many more space to move around without fear to scratch some object.
     
  14. Sep 17, 2014 #13

    boneh3ad

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    Airships rely on an entirely different concept for flight. They are lighter-than-air vehicles, and thus use buoyancy to stay aloft and don't require large amounts of thrust to stay afloat. Planes, on the other hand, are heavier-than-air vehicles and require forward motion to stay aloft.

    An airship remains stable simply due to the fact that the buoyancy force is acting at a point above the center of mass of the whole vehicle, so if it were to tip one way or the other, there is a natural restorative torque that would tend to rotate it back to its upright position. If you had just a cylinder relying on lift, orientation doesn't matter, much like a rocket, and you would need to have some kind of control surfaces to maintain stability. Presently, those control surfaces are integrated into the wings and tail. This is one of several reasons that wingless designs are not just tubes.

    In what modern instance have the wings just fallen off of a plane? Regarding clipping objects with wings, that rarely happens and is always a result of human error. You can solve that problem by procedurally rather than structurally.

    There's a reason you don't see wingless flying animals. It isn't an efficient means of flight and requires a large amount of thrust per weight to achieve compared to winged flight, so natural selection simply wouldn't allow it to evolve that way, as any organism would be simply be outcompeted by winged animals.

    Also consider that the solar planes that are built these days and the planes built for long-duration flight both must be very efficient in generating lift (have a lot of lift per unit weight and thrust) in order to achieve their flight goals, and the solution there is always to make bigger wings. The stubbier the wings (or removing them entirely) is simply extraordinarily inefficient compared to winged vehicles.
     
  15. Sep 17, 2014 #14
    For example:
    They use wings as the only way to generate thrust, therefore it is not an absolute prove.
     
    Last edited by a moderator: Sep 25, 2014
  16. Sep 17, 2014 #15

    russ_watters

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    That's a famous viral marketing hoax. In reality, wings ripping off of airplanes is pretty rare.

    This thread needs to get more serious.
     
    Last edited by a moderator: Sep 25, 2014
  17. Sep 17, 2014 #16

    boneh3ad

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    That's not real, has been proven to be fake, and doesn't even look real.
     
    Last edited by a moderator: Sep 25, 2014
  18. Oct 3, 2014 #17
  19. Oct 3, 2014 #18

    Simon Bridge

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    ... anything will fly if you throw it hard enough.
    Not thrown hard enough - then I guess it could fly downwards.

    You are not the only one to think airships could make a comeback - but they have serious drawbacks i.e. they are slow, difficult to manouver, strongly affected by wind, and large for their carrying capacity.

    You are not the only one to think of doing away with those pesky wings...
    Short or no wing aircraft are highly unstable - which makes them more manouverable (deliberately unstable designs are used for warplanes) but they tend to be small and need to go fast to work.

    Redirected jet thrust, as in the Lippische or Dornier Aerodyne (artwork post #17) use another principle again - lift is produced by directing some of the engine thrust downwards. The same job is usually better done with a helecopter. The Harrier used the principle for vtol, but also used wings for regular flight.

    There are lots of novel approaches to flight - the trick is to figure what problem you want to solve.
    Anyway - your original question is answered: the concept in post #1 is not practical and won't fly because of drag.

    Suggest you review basic aerodynamics before posting yet another concept.
     
  20. Oct 4, 2014 #19

    I just thought to take the best from airships and planes. A levitating transport is a common element in sci/fi.
    What could make ships to levitate with exception of buoyancy?

     
    Last edited by a moderator: Oct 6, 2014
  21. Oct 4, 2014 #20

    Simon Bridge

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