Partially Powered Rotor

[Jens]

Partially Powered Rotor - don't seem to be much in use.

Look like the Lfino is using it:

Normal operation is to apply about 12% of propeller power to the rotor via a power splitting differential
20200

If we look at the Partially Powered Rotor theoretically, and only from an efficiency viewpoint - forgetting at first about the mecanical complications, added weight, "tail rotor", maintance and safty isues etc. - you should be able to save some hp's - I would believe.

Eksample:
A gyro have 40 hp, and need 10 hp more, so we only have to ad 5 hp directly into the rotor. Or...?

How many % do we save? More or less than 50%?
How many hp's would be best to put into the rotor from an efficiency viewpoint?

What does the theory say about this.

[C. Beaty]

Jens, the power consumed by an unpowered rotor must be extracted from the wind, exactly the same as a windmill.

If the rotor has a windmill efficiency of 60% and the propeller efficiency is also 60%, then the overall efficiency is 36%.

Direct mechanical drive will have an efficiency of more than 95%.

The rotor of a machine in the range being discussed here may consume 40 hp at cruise speed, or 40/.36 = 111 hp if driven pneumatically, but only 40/.95 = 42 hp if driven mechanically.

Of course, 40 hp applied to a rotor running at 290 rpm is out of the question due to torque difficulties without a tail rotor but the power saving with 12% of propeller power applied to the rotor is in proportion.

[Jens]

Jens, the power consumed by an unpowered rotor must be extracted from the wind, exactly the same as a windmill.

If the rotor has a windmill efficiency of 60% and the propeller efficiency is also 60%, then the overall efficiency is 36%.

Direct mechanical drive will have an efficiency of more than 95%.



Very well - that make sense.
That mean's ALL lift comes from rotating the rotor?
That would be new understanding for me - if I have got this right.
So far I had some dim idea, that you need some hp's for rotating the rotor and after that, the rotor worked as a kind of plane/fixed wing. Maybe it is NOT so?

The word "Gyroplane" is not good then.

Maybe I have one more misunderstood:
So far I was thinking the gyrocopter where more efficient than the helicopter - I am not so sure about that any longer :confused:

[scottessex]

Gyro's are about the most inefficient way to fly, all the air required to turn the rotor is drag, just like a parachute.

All that the powered rotor does is increase complexity, weight, cost and maintenance.

Although the LFINO is VERY impressive, it is slightly beyond the normal homebuilders skills to build.

Gyro's are simple, that's all, simple, there is no need to complicate them.

[PW_Plack]

Scott said...

All that the powered rotor does is increase complexity, weight, cost and maintenance...

No, it also gains more speed for the same HP.

Gyro's are simple, that's all, simple, there is no need to complicate them...

Why do some enthusiasts talk down attempts to do more with the gyroplane? I'm building a simple machine to fly myself, but I love seeing people with the talent and ambition of Dick and Ernie try to advance the state of the art.

[C. Beaty]

Jens, the gyroplane is less efficient than the helicopter but the helicopter suffers in the upper speed range where the rotor must provide both lift and forward propulsion.

The most efficient combination is to supply sufficient mechanical power to the rotor to enable it to fly perfectly flat and provide forward propulsion by an ordinary airscrew.

[scottessex]

PW, I am not trying to talk down anyones attempts at anything,
The gyro is beautiful in its simplicity, basic simple.
If a powered rotor was such an improvement, would it be common place? would it be affordable?
I have nothing but respect for Dick and Ernie, true geniuses no doubt.

Didn't mean to rain on anyones parade, but after asking myself all those same questions before I learned to fly gyros,
I'd rather fly and enjoy the ride, than sit on the ground and dream of flying, that is all.

[C. Beaty]

“I have at last achieved perfection,” mused Henry Ford as he completed the design of the Model T.

As indeed he had in light of the time and technology.

Wood spoke wheels are perfectly adequate if the cost of labor isn’t a burden. Workers lined up and eager to earn $1 per day. No need for expensive presses to make stamped steel wheels.

“What sort of fool would go so fast as to need brakes on all 4 wheels?”

“Electric starter? If a man is fit enough to drive, he’s fit enough to crank the engine.”

“No need for fancy paint jobs. Flat black is the perfect color since it’ll be caked with mud after a few days.”

The skeptics said; “It will never replace the horse.”

[Ga6riel]

for the best ever read on Henry Ford and the US auto industry history and progression, get a hold of "The Machine that Changed the World"

[Victor Duarte]

The level of genius of someone can be recognized by the amount of morons shoughting after him.

[Jens]

Thanks very much for the informations - it has cleared some misunderstandings.
What a pleasure it is to be able to ask quistions and get answers as well.
This combined with gathering knowlegde from the internet is just magnificent :D

YES! Let us do more with the rotor.
But when we speak about the sport and learning: THE SIMPLER THE BETTER - and never leave or forget the basics - I think.

[Rotor Rooter]

IMHO.

Future rotorcraft will have powered rotors, and thrusters (propellers or very high bypass turbofans).

They will not have wings. Instead, they will have a pair of extremely rigid, large chord, variable speed, rotors.

In addition, they will be laterally symmetrical, just like all successful mobile natural life and manmade vehicles. Perhaps the first one should be called 'The Darwin'. :eek:

'The Lfino' is a step toward 'The Darwin'.

http://www.unicopter.com/Index.jpg http://www.unicopter.com/Interleaving_Very_Small.gif

[Rotor Rooter]

This thread discusses the partial powered rotor, plus the added feature of active power splitting by the use of a differential device [LFINO].

Also, the subject of improving gyroplanes while keeping the cost down is also mentioned.

A relatively inexpensive craft, with a differential device, the Gyro/Heli I (http://www.unicopter.com/0828.html), was proposed and discussed back in 2001 on the previous gyrocopter forum.

The Gyro/Heli I, and the related (but more elaborate) two other craft on this subject, Gyro/Heli II (http://www.unicopter.com/0832.html) and Gyro/Heli V (http://www.unicopter.com/GyroHeli_V.html) might be of interest.

Dave J

[quadrirotor]

Yes Dave; among all the gyro/heli, this one has the best potential:

http://www.enae.umd.edu/AGRC/Design99/Calvert.html

[Rotor Rooter]

among all the gyro/heli, this one has the best potential:

Yes, the CalVert was an impressive and winning submission. Many years ago, Paul, the lead student on the project, was also complimentary of the SynchroLite.

Today however, I would challenge anyone to a debate on the pro and cons of a more advanced Intermeshing and Interleaving configuration versus those of the current Tilt-rotors and upcoming Coaxial-ABC. :eek:

[M. Pearce]

quadrirotor,
The gyro/heli is old news. Twenty something years ago I saw one at Fort Polk military base down here in Louisiana. It was basically a Huey Helicopter with a prop for propulsion at the rear of the fuselage. It still had a tail rotor though. Amazing looking thing but the guy I was talking to said they didn't fly it anymore. I tried to buy it but they wouldn't let me get it off the base without demilling it. I'm sure by now it's in a million pieces.

[quadrirotor]

Today however, I would challenge anyone to a debate on the pro and cons of a more advanced Intermeshing and Interleaving configuration versus those of the current Tilt-rotors and upcoming Coaxial-ABC. :eek:

Yes Dave, but i am tired to debate, all has been said in former threads and posts, i don't want to give old news again!... ;)

[quadrirotor]

Again the illustration of an old news!!! ;)

http://www.cartercopters.com/images/ctd-t_2006-01-16/ctd-t_2006-01-16_short_takeoff_1.html

[C. Beaty]

While you guys sit around and debate how many angels can dance on the head of a pin, Dick DeGraw has designed, built and test flown partially powered rotors as well as synchropters.

[quadrirotor]

Old news, Chuck, every one knows that Dick Degraw is a wizard!!! ;)

[Vance]

I have found that if I am around wizards enough I can learn to do a little magic myself.

I have not found much value in being board by what people have done and are trying to do.

Thank you, Vance

[Rotor Rooter]

Help. http://www.unicopter.com/Drowning.gif
Then on further thought ...........

[gyrofly]

Somehow I think that we would all be better off in the USA, and maby the world, if everyone did not have an automobile. The country may have evolved a bit differently with a mass transit type of deal instead of everyone having an auto. I am viewing autos as much as the evolution of the PC. Why should everyone have a PC? Would not it be better if there were just dumb terminals out there with a main frame brain that that was upgraded to respond to changes in the tech. instead of having to upgrade our individual computers and software every year? Bill Gates would surely not be the PC baron he is and I think the world may be a bit safer because of it.
A thought...