New rotorcraft concepts

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joe nelson

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Jan 9, 2008
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Cincinnati,Ohio
Auto,

The ornicopter go in the opposite direction to what I'm doing. My intent is to make rotary wing flight as simple as possible. The use of thing like strap packs in lew of hinges and servo flap for ease of control and to minimize resonance is the route that I'm taking. So far, the progress has been slow but I'm alot farther along than two years ago when I started.

I have learn to build my own blades with help of Bob Kelly and how to balance them. I've machined my head and had a machine shop lazer cut my straps. Needless to say the curve is wide but I'm still pitching.
 

davh12

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Nov 21, 2009
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154
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Abingdon, IL USA.................military moves ev
Hey folks,

Birdy,
I noticed you asked about unusual rotorcraft. I was wondering what all of you might think of this concept. I've got a patent in the works and it left the classification contractor. I presented this concept to DARPA. They said the work in my outline had merit, but felt the pay was not high enough for DOD to "Advance the state of the art" as they called it. But according to some the "industry" usually pays no attention to the private sector and "small entities" such as myself. I did get a call from Bell Helicopters and they were up front with me. They would've considered looking at my design, but the guy I spoke with in the XworkX told me that Bell's legal DEP. told him hands off because I'm still active duty army. I'm not in aviation. I've always been Infantry, but I have a cognitive interset in rotorcraft and someone once told me that I could not do this, so I had to do it anyway. I'm working on a small scale proof of concept prototype. www.envisionhelicopters.com is my newly created site, but it's still not finished and it may not pop on google because it's too new. Any of you rotor heads got any suggestions about anything I've mentioned?. Thanks.

David
 

HumanPoweredDesigner

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Sep 6, 2009
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1,030
Location
Arizona
Just a side not here to rtfm's post - the fixed wing/rotor hybrid was considered for a number of years to be the ideal mix between airplane and helicopter, to the point where even our mainstream organizations started in on the concepts. Several built interesting POC vehicles but none ever made it anywhere. One of the key issues to address with the design is what do you do with the blades when you're at cruise?

The problem with blades is that they get part of their structural characteristics from the rotation. The centripetal acceleration of the rotating mass provides the blades with a certain amount of stiffness, which allows them to produce a substantial amount of lift despite the small, very high aspect ratio area. Coupled with the rotation, the lift they produce also provides a bit of structural stability.

When you remove a large part of the lift by depending on the wings in forward flight, you end up with essentially floppy wings (the rotor blade of course) at the top of your craft. This is especially a problem when you slow the rotor down, or even worse, stop it entirely. The cruise situation then becomes one where you have to be especially worried about flutter (a function of true airspeed) and structural divergence. The result would of course be that the blades might depart from the craft at cruise, or possibly flail it to death.

This is why several of the mainstream concepts went to very wide chord but short span rotors. But of course at that point they became lousy helicopters, and not to mention, loud (higher rpm).
By hybrid, are you referring to airplanes with an engine on each wing, but one of the wings can change AoA 180 degres, and then both wings can pivot like a helicopter whose power comes from the smaller props for take off? And after vertical lift off, it somehow gets the other wing back around and then flies like a plane?
 

jlawren3

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May 29, 2011
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Location
Palm Harbor, FL 34683/ USA
There is now a new rotorcraft technology: the tiltplane. Most people would naturally assume that helicopters and airplanes plus a few miscellaneous aircraft like hovercraft, gliders, and auto-gyros comprise the complete world of aircraft. But another new aircraft has emerged. It is a rotorcraft with two coaxial rotors turning in opposite directions about a streamlined fuselage, one rotor being about 1/4 of the length of the fuselage from the nose and the other rotor being about 3/4s of the length of the fuselage from the nose. See Welcome to Tiltplane.com | New VTOL Concept.

A tiltplane takes off with its fuselage oriented vertically, but tilts over as it picks up speed to cruise with its fuselage oriented horizontally. To land it pulls its nose up while slowing down and it then backs down and lands with its fuselage oriented vertically again.

At a glance this may all seem a bit awkward. Why, you may wonder, would anyone want to pursue such an aircraft design? Wouldn't it be a lot simpler if, for example, this craft could be made with a single powered rotor up front and a fixed wing in the rear? Wouldn't that work well enough?

Well, it would not be able to get through transition. In transition the craft is initially flying somewhat sideways as it tilts over and picks up speed. If the craft had its only rotor up front, then that rotor would "see" air approaching at a good velocity on one side because the craft's velocity would be added to the advancing rotor blade's velocity. But the fixed wing in the rear would only "see" air approaching at the craft's velocity, a velocity far too low to provide the lift needed from this rear wing.

OK, so both rotors are needed. You'll have to admit that powering two rotors makes for a complex aircraft. How is this complexity justified?

There is a very remarkable fact about tiltplanes: the area of their rotor blades should be a lot less than the area of the wings and control surfaces of fixed-wing aircraft. This is possible because the wings of conventional aircraft have to provide the lift needed to lift the aircraft at its takeoff speed which is relatively low compared to the airspeed seen by the rotors of tiltplanes. When cruising the rotor blades of tiltplanes will make long shallow spirals through the air. Because of their comparatively small surface areas, the drag of a tiltplane's rotor blades when cruising will be a lot less than the drag of the wings of conventional aircraft.
 

joe nelson

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Jan 9, 2008
Messages
265
Location
Cincinnati,Ohio
Don,

That's a beautiful bird! Now, I see why you were interested in the Locheed designs! If I win the lottery, I would buy one!
 

Birdy

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Aug 16, 2008
Messages
45
Location
Central Australia
A tiltplane takes off with its fuselage oriented vertically, but tilts over as it picks up speed to cruise with its fuselage oriented horizontally. To land it pulls its nose up while slowing down and it then backs down and lands with its fuselage oriented vertically again.

Hate to be around wen [ not if] the noise stoped, in any phase of flight.
 

D Hillberg

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Nov 23, 2010
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1,232
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very low low low earth orbit
Bell used Berch, balsa,Mahogany,& spruce. Gyrodyne used all spruce in thin plys & Glues autoclaved to shape. The H 21 had ply skin on wood ribs on a steel spar tube. Take your pick. it's all good.
 

EzyBuildWing

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Joined
Sep 23, 2009
Messages
51
Location
Sydney NSW Australia
Here’s the way to go:
Watch the fantastic "Electric Pre-spin" at the begining of this "Hungarocopter" vid….sounds much better than a turbine start-up…… hear the solenoids clunk in:
https://www.youtube.com/watch?v=X8tUT74YgWo
Once the powerful electric motor pre-spins the rotor up to rated-speed at zero-pitch, the petrol-engine starts up and takes over 100%.
The electric-motor then becomes a generator and charges the battery.
If petrol-engine quits, then the electric motor immediately kicks in for a few minutes thus enabling a (semi)power-on decent, and a smooth flared landing.
Click this Link for excellent websit and pics of the electric motor-generator: http://hungarocopter.hu/hu/mentorendszer It's beautifully elegant & Heli looks brilliant to fly.
It would be nice to see such a heli powered with a lightweight all-Aluminium "peripeheral-ported" 13B Mazda Wankel.
That these 13B engines are reliable and tough, is an understatement! They can run all day easy outputting 150HP at 5000rpm continuous. And so smooth!
Check this Link for the 700HP turbo’d 13B’s time-to-climb record: 10,000 ft in 100 seconds! Absolutely awesome.
https://www.youtube.com/watch?v=k_gedJrWbT4
 

henryk

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Joined
Mar 8, 2010
Messages
5,154
Location
krakow,poland
-my Fellow was invented new type of rotorcraft=autogyro with conter rotating
rotors drived all flying time=with max power in VTOL regime and low power
in cruise regime.

=the electric energy is generated with starter/generator maschine drived via IC motor.(for long time fly).

this motor drives conter rotating propellers for thrust (high speed,low rotor drag).

BTW=specific thrust is 3-15 kG/kW (95 kG/qm and 12 kG/qm)
 

EzyBuildWing

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Joined
Sep 23, 2009
Messages
51
Location
Sydney NSW Australia
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