We are building a manned copter with a gasoline engine and propellers with variable pitch.
In order not to repeat itself - very detailed information is available on our website - https://flying-bike2018.com/home/
A small video report - on this video!
Before asking questions or commenting - a big request - read the description of the project on the site. I tried VERY MORE to describe my arguments.
As the construction of the Copter progresses, I will publish new information.
I was wondering why nobody has gone for four ducted fans, which would give greater thrust and be just as controllable.
The opinions and statements of this poster are largely based on facts and portray a possible version of the actual events.
Measure twice, cut once...
scratch head, shrug, shim to fit.
Flying an RV-12. I am building a Fisher Celebrity, slowly.
Um, no.
Something that actually works!
In the design of this thread, a LOT of complexity could be removed by simply using ducted fans instead of four sets of variable pitched props.
I also wonder why he doesn't keep the electric motors and simply have the gas engine run a generator, if he's going off the shelf as much as possible.
But HUGE kudoes for not calling it a "manned drone." I really, really hate that.
The opinions and statements of this poster are largely based on facts and portray a possible version of the actual events.
Originally Posted by Frank Giger
As I recall, numerous experiments in wind tunnels have shown that propellers in annular nozzles have a higher efficiency only in the case of very precise manufacturing, with a minimum annular gap.
But the increase in thrust efficiency is "eaten up" by the greater weight of the ring nozzle and the increased air resistance.
Therefore, despite the seemingly high efficiency, in practice no one applies.
And besides, the mechanism of turning the propeller with a ring nozzle is of great weight and complexity.
The design of the variable pitch propeller, which has been used for many decades in hundreds of thousands of aircraft and helicopters - is simpler and more efficient.
As for the gasoline engine with the generator - look at the weight of the generator. The power of at least 100 kW.
And the efficiency of the "bundle" gasoline engine - generator - electric motor - is also low.
It's good for ships. It was tried during World War II by Porsche on the "Tiger" - Panzerkampfwagen VI "Tiger P" VK4501 (P).
But for airplanes - it is still difficult and uneconomical.
That was kind of my point. So far I don't think anyone has made it work.
Measure twice, cut once...
scratch head, shrug, shim to fit.
Flying an RV-12. I am building a Fisher Celebrity, slowly.
Well it worked for Moller, he managed to entice a lot of people to give him money for something that never got out of ground effect (and even not overly stable there).
[QUOTE=Ihor Nastashchuk;68841]We are building a manned copter with a gasoline engine and propellers with variable pitch.
A couple of questions:
1. Are the pilot/pax sitting in the plane of the blades? What happens when one lets go?
2. Do the blade disks have sufficient mass to autorotate? What happens when a gearbox goes Tango-Uniform at a hundred feet?
3. Your VPP is not "used on hundreds of thousands of radio-controlled helicopter models" because it supplies collective pitch control only. You appear to rely on differential thrust from the four blade disks for your "cyclic". Is this the only engineering misrepresentation/ignorance you are displaying?
If you're lucky, you'll attract only half the lawsuits that Moller did.
Ihor, if they lose power, airplanes can glide under control and helicopters can autorotate to a probably survivable landing. But if your quadcopter lost power to one or more propellers, it would flip and accelerate to the ground, tangling up the parachute if it could even be deployed. I think you ought to redesign it to survive the failure of any one component.
"...misrepresentation/ignorance you are displaying..."
I advise you to refrain from rudeness, but first learn to read carefully!
1. It is evident in the figures and in the photo that the pilot sits above the plane of rotation of the propellers.
2. I already answered this question - propellers with a high load on the area are NOT autorotated!
3. I already answered and this question. For VERY DARK AND LAZY - I repeat - will be the same as with a helicopter, which broke the reducer!
Only in difference from the helicopter (I repeatedly REPEAT) - I have a system of parachute rescue.
Yes, instead of changing the cyclic pitch on one propeller, like a helicopter, I applied a change in the overall pitch on the four propellers.
Why is this ignorance?
"...If you're lucky, you'll attract only half the lawsuits that Moller did..."
With my luck, I'll figure it out myself, without such advisers!
"...if they lose power, airplanes can glide under control and helicopters can autorotate..."
You're right. But only partially.
The helicopter will be autorotated if the engine has decayed and the propeller does not get stuck. If it sticks - no autorotation.
If the blade breaks - the same - there will be no autorotation - the helicopter will fall.
The plane will only plan if the engine has decayed. In the event of a breakdown of something else - a wing, a stabilizer, or even a flap or aileron - the airplane is likely to fall.
That is - the ability to plan or autorotate - depends on what a breakdown.
But it does not bother anyone - everyone flies.
So with my project. It depends on what will break.
100% guarantee can be given in this life only one - WE ALL DIE, sooner or later. All the rest is just a probability!
A parachute is a way to reduce this probability!
Besides - why should it break?
Look at it.
In comparison with these propellers, mine are just a coffee grinder!
But on helicopters this heap has been flying for decades!
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