Sailplane with a Extremely Small Electric Motor (1.5kw)

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jedi

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Prior designs:

An 86 degree Rogollo with 4 degree billow, 20 foot LE tubes and speed bar. Weight less than 40 pounds, cost less than $100. Flew well for the day.


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Same 20 foot LE tubes in a 42 foot span flying wing. 7 foot root cord shown. Limited ground testing indicated more work was needed for CG and stability issues as well as ground handling and improved sail lofting. Span was determined to be to large. Current designs target 32 foot span with better attention to the wing tip aerodynamics.

image.jpgimage.jpgimage.jpg
 
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stanislavz

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Its all depend on goal. Just take good floater type glider (Marske Monarch, Carbon dragon, ULF) - and add for it motor. Their all do come in L/D in 20 or more range in that 200 mtow range it takes 10 kg range of thrust for level flight. And this is a level of any bigger drone motor. Or motors ~ 3-5kw of power..

And in beeing in 3-5 kwh range it would weight 20-30 kg... which is kind of overkill i think.
 

jedi

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1. 23 kg = 50 pounds at 1 G or 75 pounds at 1.5 G (post # 23 - 20 to 30 kg motor + batteries)
2. at 1.5 cycles per sec = 90 cycles per minute flapping cycle for reference.
3. 5 hp = 2,750 ft #/sec = 247,500 ft # / min
4. 247,500 ft # / min / 75 # = 3,300 ft / min
5. 3,300 ft /min / 90 strokes per min = 37 ft / stroke - stoke is too long for flapping propulsion.

But include the weight of the pilot, etc. 50 pounds plus 200 ponds = 250 pounds
1. 250 pounds at 1.5 G = 375 pounds
2. 247,500 ft # / min from step 4 above
3. 247,500 ft # / min / 375 # = 660 ft / min
4. 560 ft / min / 90 cycles /min = 7.3 ft / cycle - ok for bird flapping but not for rigid PO
PO = (Pseudo Ornithopter)
5. If 1 hp is sufficient for improving L/D to 50:1 then stroke is reduced to 1.5 ft (7.3/5 = ~1.5)
6. A 1.5 foot stroke is equivalent to the pilot doing squats and is adequate for a limited amount of PO propulsion.

The weight of the motor and batteries added to the pilot weight and to assisting the pilot is what makes this propulsion system a possibility for a light weight glider to greatly improve max L/D performance. And there is no power off propeller drag.

The cycle frequency needs to be similar to a workout of jumping jacks, pushups or squats in order to not be uncomfortable. The motor and battery capacity is only limited by weight and can be sized to reduce the power input of the pilot to a level that is compatible with the pilot's capabilities. The weight of additional batteries adds to the power output possible without the necessity of increasing the stroke or frequency to undesirable levels.
 
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henryk

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what makes this propulsion system a possibility for a light weight glider to greatly improve max L/D performance. And there is no power off propeller drag.
"
performance deployable flying devices (for example, hang gliders oF the class 2
of FAI-CIVL regulation). This wing can be based on the application of the
cable or tube leading edge arrangement. Its actual and possible future lift-
drag ratio is compared in figure i0 with that of other ultralight wing types.

Because of the possibility of high L/D, it is very suitable for oscillating
wing propulsion of hang gliders (ref. 5) and has been practically proved and
tried by the author in 1976-1977 by use of an elastic pilot harness and foot
straps. "

from=


+ "Idea napędu oscylacyjnego. "

from=



PS=its clear ?

PS2= my version =device for "OSCILATING wing propulsion=for old pilotes=

 
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John.Roo

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Probably best videos with human powered really "flown" ornithopter...
With both eyes a bit closed :cool: we could call it flight even if takeoff has been done with car towing and during flight we could see only 16 "wing flaps". Really looks to you like simple way to fly for "normal" pilots? ;)



And crash...
 
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John.Roo

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This airplane has beautifull "retro" design 👍
1961.jpg
2 hp for takeoff, 0,5 hp for horizontal flight.
Designed in 1961....

"A man-powered flight at a Hampshire airfield has taken place to mark a historic flight made 60 years ago. Powered and piloted by Robin Kraike, Airglow a pedal-powered aircraft took off from Lasham airfield and flew for about 1 mile (1.6km). The original flight took place on 9 November, 1961 in Southampton University's Man Powered Aircraft, (SUMPAC) piloted by gliding instructor Derek Piggott." 👏
 
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henryk

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simple way to fly for "normal" pilots?
=42 kg, 32 m span=big constructors achiwemant (technology) !

"Размах крыльев – 12 метров, площадь – 14 м2, удлинение l=20. Вес конструкции – 63 кг." =not so good construction, but much better kinematic and dynamic...

see Pic 5a=

 

jedi

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from post #38 reference:

"Loutzkoy’s patented idea was to use two engines to power separate propellers of different size on a common shaft, rotated at different speed the same direction."

I think this is a good idea. This can be easily done with one engine and it also provides a PSRU to function with today's high speed engines.

Henryk - At first i thought this is what you were doing with the counter rotating propellers but I now see that your system appears to be like many others before.

This subject should have it's one thread. I would like to work with anyone who would like to make a demonstration model. Any volunteers?

I can provide some hardware if we can get a project going in either the Pacific Northwest or AZ state.
 
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