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Dual Centrifugal Blower Drone

Better to hide away the spinning parts for noise and fragility reasons
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The public knows about drones, they're wrong in most cases. What they're usually referring to is piloted hobby grade through to semi-professional aircraft most often used as camera platforms. The most common design for these is the quadcopter, 4 brushless DC motors spinning propellers at the ends of a rough X-shape with the batteries, controllers, and radio gear in the middle. The position of the propellers at the periphery makes them vulnerable to damage whenever the quadcopter hits anything, which is often.

To solve this, we can do a quick re-design. The main body in the center of the craft now contains a centrifugal blower spinning about a vertical axis. The air intake is at the top of the craft, air is compressed by the blower and exhausted through 4 tubes in the familiar X-shape. At the ends of the tubes, rotating nozzles direct the exhaust, mainly they will be directing it downward for lift. Small sliding valves can control air distribution to each of the 4 tubes and the rotating nozzles add additional control finesse.

The central blower, when accelerated/decelerated will impart torque on the whole aircraft. This could be countered by angling the nozzles at the end of the tubes. The smarter way would be to have 2 motors driving two concentric counter-rotating centrifugal blowers. By controlling the two, changes in thrust can be made with no net torque. Better yet, rotation of the craft can be achieved by speeding up one blower and slowing the other to cause torque with the same net thrust.

Because most of the force generated goes to opposing the aircraft weight, there's no actual need to have it generated at the ends of the X-shape, instead, a central exhaust constituting 50-90% of the thrust would be more efficient, and could perhaps be varied depending on the maneuverability requirements.

The tube-nozzle design will have some pumping losses associated but these can be offset. Larger motors are often more efficient than multiple small motors per unit of output. The tube nozzle system is used to good effect in quieter helicopter tail rotors <link>. The advantages should include lower noise, increased robustness and overall more flying saucer-like aesthetic, combined with spooky apparently reactionless rotation ability. The centrifugal blower with axial input will essentially operate like one of those fancy turbocharger compressors, all the work has already been done there.

bs0u0155, Nov 13 2018

Tube-Nozzle Helicopter https://en.wikipedia.org/wiki/NOTAR
[bs0u0155, Nov 13 2018]

Avro Canada VZ-9 Avrocar https://en.wikipedi...Canada_VZ-9_Avrocar
"...proved to have unresolved thrust and stability problems..." [8th of 7, Nov 13 2018]

"Monocopter" jetpack http://www.technolo...ody_monocopter.html
Like this idea, except axial instead of centrifugal, engined instead of motored, and a jetpack instead of a drone. I haven't seen any updates in many years. [notexactly, Nov 14 2018]

Hackaday post on the same https://hackaday.co...test-pilots-wanted/
Some more links, info, and arguing in the comments [notexactly, Nov 14 2018]

This is NOT a Propeller https://www.youtube...watch?v=wg8ZbiC9IBw
Another type of small aircraft powered by a centrifugal blower, built by the late [Samm Sheperd] [notexactly, Nov 14 2018]

[link]






       A model Avrocar, then ?   

       <link>
8th of 7, Nov 13 2018
  

       //A model Avrocar, then ? //   

       Without the control problems, heat build-up and nuts triple jet to central fan gearbox (I assume, can't actually see how the fan was driven)
bs0u0155, Nov 13 2018
  

       The control problems will still be there, only they're probably manageable by contemporary electronic flight control systems.   

       Although an Avrocar-like vehicle is probably practical now, it would still suffer from many of the same limitations as the original; very limited payload and endurance, low power-to-weight ratio, complexity, heat management, noise and vibration.   

       It would actually be worse than a helicopter, an extremely difficult thing to achieve.
8th of 7, Nov 13 2018
  

       //worse than a helicopter// you saw it here first.
MaxwellBuchanan, Nov 13 2018
  

       It strikes me that would-be flying car enthusiasts could learn something from the world of ballooning.   

       It is possible (and has been tried) for a complete idiot to tie sufficient helium balloons to a deckchair to become airborne - something that full-size-balloon balloonists probably train for years to be able to do.   

       So, translating this into drones, the best and safest way to fly would be wearing a harness to which, say, 40-60 standard consumer-grade drones are tied. Just program them all to stay in formation, and you're good to go. High redundancy means that a few failed drones won't be immediately fatal. Moreovermore, the noise from 40-60 small drones will be much less intense than from one vast ducted fan.   

       Assuming that drones can be bought in bulk for £200 apiece, that gives you a viable commuting option for less than the cost of a modest car.
MaxwellBuchanan, Nov 13 2018
  

       //worse than a helicopter, an extremely difficult thing to achieve//   

       Throw enough money at it and you can do anything. Did I mention that I can make this stealth? I can also do sensor fusion, and I've got this great idea about beginning the manufacturing process before I've finished developing it...
bs0u0155, Nov 13 2018
  

       // Throw enough money at it and you can do anything. //   

       Yes, that's the approach the Pentagon* has always used.   

       // Did I mention that I can make this stealth? //   

       No; but the "black triangle" aircraft that fly out of Area 51 are already doing well in that technology, and we don't mean the F-117 either.   

       // wearing a harness to which, say, 40-60 standard consumer-grade drones are tied. //   

       Some Scandiwegian nutjob has already done something very, very similar: a sort of "hoop skirt" built with many small drone motors.   

       *Not the common synonym for the U.S. Department of Defense, but the secret worldwide conspiracy run by an evil alliance of representatives of the Templars, Masons, Jesuits, Mafia, Illuminati and Mrs. Amelia Nugent, secretary of the Berkhampstead branch of the Women's Institute, who took a wrong turn and went through the door marked STAFF ONLY on the day that the secret password just happened to be "Blackcurrant jelly",   

       Oddly, Amelia fits right in, and the other conspirators appreciate the marked improvement in the quality of the refreshments.
8th of 7, Nov 13 2018
  

       //but the "black triangle" aircraft that fly out of Area 51 are already doing well in that technology//   

       There's silly money flowing these days. Just a few decades ago* chocolates were delivered by ladder and not stealth drones.   

       * Although the green foil triangles could have been a hint as to what the R&D departments were working on.
bigsleep, Nov 14 2018
  

       // green foil triangles //   

       That's not all ... the purple ones with the brazil nut in them are dead ringers for the B2 Spirit's engine intakes ...   

       There's something going on that They don't want you to know about. Sinister stealth experiments with popular confectionery is only the start.
8th of 7, Nov 15 2018
  
      
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