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The future of the helicopter is electric.

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The future of the helicopter is electric.

Old 4th Sep 2011, 19:35
  #81 (permalink)  
 
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Yes. The lithium-ion batteries are one of the risks that exist in the development of this new type of helicopter.

The batteries have a combination of conduction and convection based cooling.

The large movable rudder is an addition to minimize cross-couplings, as the project develops. Pascal has joked that he should have made it out of bamboo.


Dave
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Old 5th Sep 2011, 17:35
  #82 (permalink)  
 
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Great! Thanks for posting this, Dave. Looks a lot safer than putting a match to AvGas - you check all your fuses right?

Interestingly there is no real performance disadvantage, in terms of power to weight, with LiPo over internal combustion. Hybrids using LiPo & fuel cells seem to be hitting the mark in fixed wing aviation. There are already some other fixed wing projects going "commercial" with fuel cells now that the concept has been demonstrated by Boeing/Diamond/Intelligent Energy:

ENFICA-FC - ENvironmentally Friendly Inter City Aircraft powered by Fuel Cells

Actually, there may be some serious benefits to electric power in helicopter pilot training. If all you need to do is hover around the airfield, along with a couple of circuits, then this may be a much more cost effective approach. No more TBO to drive costs up and no more expensive development into ancilliaries like cooling and govenor control. The powertrain can be relatively simple with minimal vibration mounting, ideally with rotor system optimised for hover efficiency over cruise efficiency. Just make sure there are a couple of power packs on standby near the hanger, even recharge time is no longer a big headache.
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Old 5th Sep 2011, 19:10
  #83 (permalink)  
 
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Hi Mart,

The feat was released on Gizmag last night. It gives more information on his craft and the initial flights.

Modern-day aviation pioneer achieves world's first untethered, manned electric helicopter flight.


He has much more work to do, but it is the start of manned electric rotorcraft.

Dave
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Old 6th Sep 2011, 11:26
  #84 (permalink)  
 
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How long to recharge? Li-Po batteries are not fuel cells are they?……..and all because of the myth of global warming/climate change…...
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Old 6th Sep 2011, 11:52
  #85 (permalink)  
 
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The distinction between various electric powertrain technologies is becoming more blurred as performance improves. A fuel cell uses some kind of hydrocarbon fuel, with hydrogen favoured for transport applications but heavy oils possible for static applications (steam reformation used to break down into H2 and CO2). Lithium-Polymer batteries are the latest generation of energy storage device but are capable of extremely high rates of charge and discharge. Often the two technologies are combined to allow fuel cells to trickle charge LiPo batts in between demand peaks. For constant high power applications like helicopters this approach is of limited use, but LiPo will eventually give way to true high power to weight fuel cells. When will this happen? Eventually...
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Old 7th Sep 2011, 18:01
  #86 (permalink)  
 
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Pascal has asked that this link be posted on PPRuNe. It provides more information on his craft, and a respect for the support he received.

First manned electric helicopter flies


Dave
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Old 8th Sep 2011, 17:51
  #87 (permalink)  
 
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Looking at the photos, it's interesting to note that there is no collective pitch mechanism or sprag clutch in the drivetrain - that would worry me. This will likely be the main area of development before getting out of ground effect. Interesting to see if a conventional swash plate, with cyclic mechanism, makes it into the design too. Power reserve would also allow higher inertia rotors, which will help desensitise control for improved dynamic stability, as well as extra margin for when the batteries run flat.

That yaw setup with a potentiometer on each pedal controlling motor rpm is interesting, although I can't imagine rpm controlled collective to be easy. If collective mechanisms are fitted then differential collective yaw control will likely be fitted, but this will lead to force control rather than velocity control. If all of the control headaches like reduced yaw authority in autorotation are to be avoided it would be a pity if some kind of differential velocity yaw system was not kept. As long as motors are reliable then they may as well stay there, even if put through a geared differential. Even in autorotation the motors will quite happily transfer power from one rotor to the other.

That landing gear is subtle but clever, if I see it right. The skid struts point to the centre of mass, while being suported from below by tensioning bungees. This allows for some landing energy adsorption, and will not try to topple the machine if a skid touches down in sideways flight. Instead the offending skid will fold under the machine pushing upward through the CG.

In summary: Some initial oversights with some clever features

In conclusion: Congratulations Pascal!

Last edited by Graviman; 8th Sep 2011 at 18:21.
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Old 9th Sep 2011, 14:20
  #88 (permalink)  
 
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Graviman:
Often the two technologies are combined to allow fuel cells to trickle charge LiPo batts in between demand peaks. For constant high power applications like helicopters this approach is of limited use, but LiPo will eventually give way to true high power to weight fuel cells. When will this happen? Eventually...
When will fusion reactors be used to generate electricity? For the last fifty years, it's been about fifteen years away from application, hasn't it?

As to power for a electric helicopter ... the latest article on graphene layers used to manufacture batteries looks promising.

Apparently, something like a 4:1 power stored to weight improvement over current best.
They say the introduction is around five years away ... but we shall see.

In re this prototype: you have a pure electrical power suppply, and your flight control commands are transmitted via electrical circuits.

Does anyone besides me see a problem with this? There is a non trivial problem with this when you get out of the laboratory.
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Old 9th Sep 2011, 17:16
  #89 (permalink)  
 
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Helicopters are far less efficient than cars....just how successful have "electric" cars been?

The only way to make a helicopter "green" is by means of paint!
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Old 10th Sep 2011, 16:29
  #90 (permalink)  
 
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"The only way to make a helicopter "green" is by means of paint!"
Like the thought
Pure electric cars are not cost effective at present, even with the UK govs bribe.
20+K for a car & that's with the bribe deducted.
How long is the life of battery pack? & at what cost, some manufacturers will not sell battery only rent, so you have a car with limited range, no instant re fill of power source, mostly small hatch models, say "Smart car" deduct battery price from purchase, average ownership of new car 3 years, 2nd owner budgets for new battery 1\4 1\3 price of new car Standard Smart say 10K electric Smart say 19K+ do the sums, then we get to a E Heli don't think viable comes into it for some time, nice idea shame about the prices.
An 80% uplift on a 300
A resume of Ecars
Electric Vehicle Costs UK | Electric Car Costs 2011 | Next Green Car
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Old 11th Sep 2011, 04:57
  #91 (permalink)  
 
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Yep-I want to fly with a Lith ion Bomb

Electric helicopters? Kaman 1950s had it , Nothing new other than "Batterys" Like i want to be fried by a bat pac, sorry it has a lot more to go for power density. Political Correct tech= Smokin Dope
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Old 13th Sep 2011, 16:38
  #92 (permalink)  
 
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I'm a new pilot and certainly no expert on electromagnetic motors, but I had an idea that I wanted to get outside views on feasibility- probably low but worth discussing, I suppose...

What about an eletric motor-powered shaft assisted by electromagnets down the length of the shaft that assist in "pushing" the shaft...this would require a rotor mast with magnets down a certain length of the shaft to be pushed, so the weight added may nix this idea from the get-go, but if not, it seems like the electromagnets around the shaft could be adjusted to "squeeze" or release the shaft in order to adjust RPM assistance. Would it not also be possible to use the rotation of the rotor shaft to charge the batteries?? Again, not an expert on this by any means and I've heard the whole self-sustaining motor has been debunked, but it's a fascinating idea. Any thoughts?
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Old 13th Sep 2011, 19:44
  #93 (permalink)  
 
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Rraetor,

If '"pushing" the shaft' implies rotating a shaft that is common to, or concentric with, the aero-rotor and the motor; then it is a viable idea. In fact, this idea has previously been done, displayed and discussed on numerous occasions, this forum being one of them.

Sikorsky liked it so much that they are still attempting to patent the pre-existing idea; to exclusion of all others.


The idea of using the airflow through the rotor to charge the batteries was also discussed on PPRuNe, on this thread.


Brilliant ideas, if I may be permitted to say so.


Anonymous
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Old 13th Sep 2011, 20:15
  #94 (permalink)  
 
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Oh, awesome- I had no idea! Encouraging to know they're not simply pie-in-the-sky notions of my own
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Old 15th Sep 2011, 02:15
  #95 (permalink)  
 
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Better title for this thread.

A better title for this thread probably would have been "The future of the light helicopter is not turboshaft".

I doubt we'll see battery technology advance enough in the next 20 years to make a pure electric helo drivetrain a commercial reality. But that doesn't mean we won't see some progress with various hybrid drivetrains.

For example, how about a set of variable frequency free-piston engines with linear generators, that cycle on/off based on demand. These engines are very lightweight and can operate at high cycle pressures, giving extremely high thermal efficiency. Their overall BSFC rate would easily be half that of a small turboshaft engine. And if you don't like electric drivetrains, how about free-piston engines and a hydraulic drivetrain? Or if you want to be carbon-free, how about a free-piston engine that operates on ammonia fuel?

To determine what approach might be best, one needs to objectively evaluate the entire rotorcraft drivetrain's particular requirements, including cost , weight, efficiency, reliability, etc. Simply taking the position that "electric is green, therefore it's the obvious choice for future rotorcraft drivetrains" is a bit closed-minded.
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Old 15th Sep 2011, 02:19
  #96 (permalink)  
 
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You will find a paperless bathroom before you get a useable elcectric helicopters with any range & payload.
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Old 15th Sep 2011, 03:23
  #97 (permalink)  
 
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hillberg, I take it you have never been based in the Middle East or Asia?
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Old 15th Sep 2011, 04:20
  #98 (permalink)  
 
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That a good one-Been to China, They have toilet paper in beijing. Never seen the middle east, Could plug that bug in a camels behind.
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Old 17th Sep 2011, 00:28
  #99 (permalink)  
 
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A little off beat is the story below perhaps, but in the 'rhythm' of things electrical and the fact that emeritus helicopter engineer Charles Kaman is quoted for the use of a clever little gizmo that we all take for granted whenever we use a strobex.
Either that or its a story that only a rock an roll guitar player could come up with?

Maybe the elctrical rotary machine could carry enough of these gizmos around to be self sustaining in current as long as heaps of vibrations were built into the invented helicopter contrivance ?

http://www.abc.net.au/catalyst/stories/3318871.htm
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Old 17th Sep 2011, 03:54
  #100 (permalink)  
 
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The future of electric helicopters and other electric-powered transportation devices lies in super-capacitors or ultracapacitors. These devices have the potential to utterly revolutionise electric power as a power source that can compete with fossil fuels.
However, the breakthrough technology is still just an arm's reach away... but it's not impossible, and it's not alchemy.

Australia's CSIRO was in the forefront of super-capacitor development in the early 2000's, but has gone quiet on it, in recent times. I suspect that it's all due to substantially higher amounts of research money needed, than the Australian Govt is prepared to commit.

The other angle is that this Holy Grail is encouraging companies such as the Texas-based EEstor, who are supposedly producing breakthrough ultracapacitors, but who are essentially making claims they cannot support with actual commercial products.

The breakthrough is supposedly in the relatively-newly-discovered ultracapacitor insulation material, barium titanate. However, converting excellent lab test results involving barium titanate into commercial products seem to be eluding EEstor... who still claim, however, to have an outstanding commercial breakthrough.

Until the day comes when that "outstanding commercial breakthrough" with ultracapacitors happens... and can be displayed as a commercial, sustainable result... companies such as EEstor will continue to generate excitement (and continue to bleed investors), without producing anything that can be considered a major breakthrough.

I have no doubt that that day will come, and it's not far off. However, it will take more money than EEstor has, or is currently allocating to research (knowing full well that companies such as EEstor are happy to rate directors substantial entitlements, and luxury company vehicles, as higher priorities than actual research expenditure).

Supercapacitor "battery" could lead to instant charging, long charge life
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