h a l f b a k e r yWe have a low common denominator: 2
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Heavily inspired by the linked idea.
As has been pointed out, a pedal-powered ekranoplan is
likely to be easier on the legs than a pedal-powered
aircraft. The ekranoplan (or ground effect vehicle) is
basically a plane designed for skimming flight a short
distance above the ground. It benefits
greatly from the
cushion of air beneath its broad wings, just as a regular
aircraft will tend to "float" as it makes its final
approach.
But.
A pedal-powered ekranoplan still has to be propelled by
a
propellor, which is considerably less efficient than
conventional wheeled propulsion.
So.
Maxco Aviation's Bikiteoplan combines the best elements
of
a kite, a bike and an ekranoplan.
At rest, the Bikiteoplan looks like your common-or-
garden
pedal-powered ekranoplan - a recumbent bike (as
described in the linked idea which I am plagiarising)
with a
pair of broad, short wings.
However, there is no propellor.
Instead, the rider pedals furiously, propelling the whole
geweirmul in a conventional bicycle-like manner, via the
back wheel.
Once a respectable speed is attained, however, the
wings
achieve sufficient lift, and the rider and wings ascend a
couple of metres into the air.
However, the wheels themselves remain on the ground.
The rider and the wings are coupled to the wheeled
bogey by a flexible sheathed steel cable (like those used
on
car speedometers), which cunningly transmits the
torque produced by the pedals to the wheeled bogey.
The
bogey itself is weighted to ensure that it remains in firm
contact with the ground.
The rider thus proceeds, kite-wise, following the
wheeled
bogey. I won't bother to go into the technicalities of
steering, since they are so obvious as to shirley require
no
explanation.
Inspired by:
Pedal_20Powered_20Ekranoplan
[MaxwellBuchanan, Oct 04 2011]
[link]
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It is borderline possible for a cyclist to spin out
the rear wheel of a bike under most conditions.
In order to make sure that this device is no easier
to spin out than an ordinary bicycle, the bogey
will have to weigh similar to the weight of the
rider. |
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The rider, therefore, will be powering both a
bogey weighing equal to himself, plus the
resistance of himself in the air. |
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Net result: Heck of a lot harder to pedal than an
ordinary bike for a slight improvement in
smoothness of ride and no other effect. |
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You'd only need one wheel, but I don't think it will work properly with the wheel in front, for somer reason. |
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// harder to pedal than an ordinary bike for a slight
improvement in smoothness of ride and no other
effect.// On level terrain, the weight won't matter
except for initial acceleration. Also, there is one
other effect - that of being above the ground,
airborne. |
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//On level terrain, the weight won't matter//
Rolling resistance will be equal, air drag will be
higher (bogey+ekranoplan) and ground effect drag
(part of air drag) will be much higher. |
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Oh and have you figured out steering? If you steer
the bogey, the plane portion will whiplash, if you
steer the plane it will fishtail as the bogey goes
straight (or ground loop, possibly). |
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Hubertus Bigend would be proud, [Max]. |
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I'm sure Otto Lilienthal didn't get where he is today
by worrying about details like steering. |
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The bicycle is one of the most effecient machines commonly used by man. Rolling resistance is very low and most of the energy used to move is involved in overcoming aerodynamic drag. |
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For an ekranoplan to work, it needs to be moving relatively quickly, so the dominant element of power consumption (aero drag) will be high. |
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I foresee the same issues as the guys who built a pedal powered hydroplane. |
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All that aside, + for the image. |
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Human-powered flight on any level has been difficult to achieve beyond a few inches at any given time. But one wonders if a multi-seat power source would be more or less efficient than a single-seater. If, say, you had 6 riders arranged in some aerodynamically and structurally efficient manner, would it take off? |
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A multiple person set-up (assuming equal athleticism of all riders) has to be more efficient, if the thing works at all. |
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For it to work a rider has to be able to produce enough lift to lift him/herself (r) and the rest of the aparatus (w). The additional apparatus weight for an additional rider (x<w) is less than the aparatus for a single rider. If a given rider can produce lift L=r+w and has a load l=r+w, two riders can produce L=2(r+w) but only have load l=2r+w+x<2(r+w) the net result is more spare lift. |
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So how come jumbo jets don't have pedals then? |
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You've never flown on Ryanair, have you, [poc] ? |
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Because L(jet engine)>>>>>>>>>>L(human) and w(jet)>>>>>>>>>>w(Bikiteoplan) |
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It is a brilliant idea, but too extreme. Why not use the ground effect to reduce the weight of bicycle and rider? It does not get the vehicle airborne, but it might allow for speeds never before achieved on an HPV. |
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