New rotorcraft concepts

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henryk

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it wasn’t successful commercially because of the noise generated by the rotor tip jet engines which use compressed air from the thrust engines pumped down the hollow blades and mixed with fuel at the tips, this prevented its primary use which was to transport passengers to and from City centres.
=electric reactionless rotors drive is completly silent and simple/light=

=Electric Motor itself works as Differential gear/reductor (NO beavales !)
 

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TFF

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Memphis, TN
Coaxial blades without controlling the lead and lag blade pitch have very limited speed ranges. Fixed pitch blades will not have constant inflow of air. The bottom blade gets really messed up. Can’t flap the blades like a normal helicopter because top and bottom will crash into each other either. The Sikorsky makes the retreating blade “ invisible “. It goes flat pitch. Inflow is not disturbed to the bottom blade. It doesn’t know it’s under another blade.
 

henryk

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Coaxial blades without controlling the lead and lag blade pitch have very limited speed ranges.
-in auer case =upper (fixed) have much smaller diameter ,
and main rotor is gyro-like ,
the RPMs are in inverse proportion...

=this configuration is self "controlled"...noise is lower !
 

rotax618

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Consider an autogyro in a glide, the best angle of glide is the lift/drag ratio of the total craft. Now if power is applied to the rotor (ignoring the effects of torque reaction), the glide will flatten showing the effect on the L/D. Even when the pre-rotator is engaged in a gyro, the gyro will become lighter. The only thing missing is a method of controlling the torque reaction. - Applying some power to an autogyro rotor in flight provides the benefits I mentioned without much extra complexity.
 

henryk

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Applying some power to an autogyro rotor in flight provides the benefits I mentioned without much extra complexity.
=Yes!

=+light , E-motor powered by light E-generator on IC pusher in cruise (low power) and suplied by
Supercapacitors (big power in short time of VTOL)

=NO heli gear, only CR Diff. gear (light & compact) for thruster !

-when capacitors are "empty"= classic autogyro regime,

iff engine quite=passive autogyro for landing.
 

Dusan

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Any edgewise rotor aircraft is having on it's best day a L/D equal to 5, but usually being about 2 to 4.5. This is regardless of the rotor being powered or not. Without transitioning to a wing-borne flight, the L/D cannot be improved and the aircraft ends up 'fighting gravity all the time', consuming a lot of power - compared to a fixed wing aircraft. The conventional helicopters have only a niche utilisation, performing missions where there is a lot of hovering involved, since they are the best hovering aircraft out there and that is due to the low disk loading. Multi-rotors are even worse, due to reduced Reynolds number on blade flow. Auto-gyro's are not capable of hovering, the utility is low, so the few aircraft out there are basically only hobby projects.
 

cblink.007

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Maryland, USA
On a related rotorcraft development note, some recent movement on an old concept:


Obviously beyond what we as homebuilders can do, but I've sat in on a number of briefings about this concept recently. It would make for a good engineering challenge if we got the green light to make a prototype!
 

Martin W

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May 14, 2021
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.

High speed helicopters are extremely expensive , use exotic engineering , and require a specialized crew

Mostly they are required for one single reason .... to be able to land and take off vertically .
The high speed is to get to the location quickly.

The smart bean counters will realize that instead of spending billions of dollars on one of those exotic specialized aircraft .... it would be easier and cheaper to just spend millions of dollars for a bunch of everyday helicopters placed everywhere they are needed.

Military insertion and extraction is different ... they require the exotic .... and money means nothing to them.

Military will use a 2 million dollar missile to destroy a 10 thousand dollar building.

,
 
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