A Helicopter for the Price of a Gyrocopter

[Ga6riel]

no
Intake, helped by ram, is pushed into the centre from above and below, and flung out to the perimeter. Any centrifugal intake pattern makes a right angle turn anyway, in some ways, this might actually improve the flow for air and pressure would naturally vector to the rear of the difuser and therefore straight onto the centrifuge. It would be necessary to use the difuser to keep the intake and rotational air in the centrifuge separate, thats about the only unusual thing.

Like some turbo chargers of centrifugal design, the eflux parts on on side of the compressor, tangental to the circumference.

[Rotor Rooter]

Ga6riel,

Sorry to not reply much earlier but I was despondently coming to the conclusion that it may not be possibly to simply 'bolt' a rotor into the teetering hinge of a gyrocopter and achieve hovering capability.

At the risk of sounding too pessimistic, your idea for a tip mounted radial blower is intriguing, but it may have terminal limitations. Some limitations might be, weight, drag during autorotation and gyroscopic precession effects.

What may be interesting is the use of a single larger version of your blower in a root driven rotor with azmith variable thrust. Of course, this is certainly not going to be a modified gyrocopter.

Perhaps the soundest remark was Larry's when he said " Assuming an optimistic 60% efficiency in using an air screw to push (or pull- same thing) the rotor around in circles, isn't this approach less efficient and more complicated than a coaxial helicopter?"


Dave

[Ga6riel]

hi Dave
well i know a lot less about the potential for success on a teetering hinge gyrocopter rotor, but i have come to agree about the rest

as to Larry's remarks
that may well be true on a pure efficiency background
but its perhaps a different story when it comes to mechanical simplicity
the centrifugal blower so fitted may not be the right answer
but i still believe that a blown rotor has significant potential
perhaps its back to the fairy ultralight and the djin

[Ga6riel]

an APU ducted into a large turbocharger provides a hot/drive side and a cold/driven side. such a setup wouldnt weigh a whole lot at all, perhaps 100lbs or so. on the voljet the hot side is used for lateral control and the cold side goes into the rotor.

or one could avoid using a gas turbine and the attendant fuel consumption and heat issues, and just opt for a conventional reciprocating engine and driven centrifugal compressor. whatever the compressor drive with this arrangement the size and weight of the compressor part are less of an issue, but is ofcourse much heavier than a turbine plant. 60 to 80hp makes for a lot of compressor.

the mast would be hollow with the teeter hinge hung around it, held captive by top and bottom bearings. this would allow a T fitting and bearing at the top with short flexible connections to the rotors. the flexible lines allow the rotor to teeter. the location of eflux jets would be dependent on the compressors performance, speed vs pressure. the only differences here with a conventional rotor are the drag of the T connection bearing and the dynamic drag of the flexible lines.

[quadrirotor]

post #24
http://www.rotaryforum.com/forum/showthread.php?t=7858

[Rotor Rooter]

Ga6riel,

A couple of questions;

Would the blades be able to have a sufficiently large X-sectional area to transmit the airflow?

Is there a means of applying collective?


From a personal perspective, I do not like the idea of a propulsor pushing a portion of the craft's mass in a direction that is opposite to the direction that the craft wants to go. [I.e. An operational propulsor on the retreating blade(s)]

___________________

The off topic portion of this post has been moved to a new thread; called Jellyfish Aircraft



Dave

[Ga6riel]

yes
and yes,
outside of the rotor propulsion its still a single rotor helicopter, and collective pitch control is the safest way of dealing with it. i just think that a fixed pitch ala model helo's could be too slow to control a decent, given there is a lot of potential for lag in accelerating the system

i think the tip-jet, for want of a better term, its potentially so small in sectional area not to matter. unlike the tip-prop it doesnt suffer from anything like the same drag regime. so its just back to translational lift rotor dynamics.

on another tack, we already know that it works as a system, but it would be better if it could use an 'off the rack' collective rotor hub like the mosquitoe's

[Rotor Rooter]

Ga6riel,

Here is an 'off-the-wall' thought for an 'jet' driven rotor. The rotor might be; a tip jet, a root jet, a strip jet along the full or portion of the span of the blade, or some combination of the foregoing.

The intent is to provide a helicopter, which has a single main rotor, the ability to produce faster forward speeds. This would be accomplished by giving the jets the ability to redirect their thrust vectors at a rate of 1 per rotor revolution.

When the blade is on the advancing side, it's thrust will be aft and this will contribute to the rotation the rotor and the advancement the craft.

When the blade is on the retreating side, its thrust will have a downward component. This will partially contribute to the rotation of the rotor, but primarily it will provide lift on the retreating side of the rotor disk. This lift will mean that the pitch of this blade will be less, the drag will be less, the blade will not be subjected to tip stall, and the craft can fly with a higher forward velocity.

____________

A second possible feature of having a 1/rev variable thrust vector might be that the blades can have a rigid attachment to the hub, ala Kaman, and the thrust vectoring be used to provided pitch change for collective and cyclic control.


Dave

[Rotor Rooter]

The Hughey Electrocopter Corporation's patent application has been released.

20060266881