Go Back  PPRuNe Forums > Aircrew Forums > Rotorheads
Reload this Page >

200hp Electric Sikorsky

Rotorheads A haven for helicopter professionals to discuss the things that affect them

200hp Electric Sikorsky

Old 14th Apr 2011, 17:47
  #41 (permalink)  
 
Join Date: Dec 2005
Location: U.S.
Posts: 155
Likes: 0
Received 0 Likes on 0 Posts
Hybrid system--??

What about a hybrid system to get around battery limitations, perhaps?

Fit a battery that's just large/heavy enough to provide perhaps 10 minutes of power for takeoff and initial climb, along with a small turbine, say APU size.

Then established in cruise at constant power demand, start the turbine, which would solely power a generator to recharge the battery. Seems to me constant power demand at peak output would reduce the inefficiencies associated with the turbine engine operation and this hybrid plant would be very efficient and reliable.

Thoughts?
arismount is offline  
Old 14th Apr 2011, 19:00
  #42 (permalink)  
 
Join Date: Apr 2003
Location: Vancouver, BC, Canada
Posts: 1,635
Likes: 0
Received 0 Likes on 0 Posts
Lonewolf 50,
.... it seems that more than trivial savings will come due to needing fewer reduction gears, and thus a smaller and lighter transmission.
Yes, the coaxial arraignment of; motor, reducer and rotor allows for the use of a planetary gearbox and this has the best power-to-weight of any reducer.
In addition, the motor can have electrical reduction and this can eliminate the mechanical gear box altogether.


onetrack,

Since the discovery and use of high power magnets there are now Permanent Magnet Motors that have very high power-to-weight ratios. In addition, the motor can be significantly overpowered for a short period of time, as long as the heat does not get too high and start demagnetizing the magnets.

Power storage is definitely the problem at present, but a lot of R&D money is looking into it.


arismount,

The hybrid sound like a good near-term solution and perhaps long-term solution for rotorcraft. Eurocopter has a video on the net, which might have been linked to on a previous PPRuNe thread. It shows a full size mockup of a hybrid helicopter. When asked about the timeline, the person being interview smiled and say that maybe in 10 years......


The above sounds like a sales pitch for electric helicopters, but we all seem to agree that electric drives and controls may eventually provide meaningful improvements.


Dave
Dave_Jackson is offline  
Old 14th Apr 2011, 21:18
  #43 (permalink)  
Thread Starter
 
Join Date: Jul 2003
Location: Port Townsend,WA. USA
Posts: 440
Likes: 0
Received 0 Likes on 0 Posts
Hi Dave,
I am working on a one seat trailerable floatplane now.
I might get back to VTOL designs when the battery technology allows for a high discharge rate with about one or two minutes of extreme power. That's all I would need to launch a fixed wing airplane using multiple electric lift fans.

The batteries should be available in few years. This system of using electric only for launch and landing is sort of what arismount suggested.
slowrotor is offline  
Old 19th Apr 2011, 11:48
  #44 (permalink)  
 
Join Date: Nov 2004
Location: Cambridgeshire, UK
Posts: 1,334
Likes: 0
Received 0 Likes on 0 Posts
Electrical systems can be developed around battery in preparation for emergent fuel cell technologies...

Intelligent energy is up to around 500W/kg using proton exchange membrane fuel cells, so only just behind Gaia batteries at 1.5kW/kg. Although Gaia batteries are only at the 0.47 MJ/kg mark, combinations of Li (just below H on periodic table) with other oxidisers may push towards H2/O2 of 16MJ/kg.

Fuel cell plane in aviation first - Intelligent Energy

Aerospace systems - Intelligent Energy

For comparison a tank of Kerosine is around the 45MJ/kg mark because the oxidiser does not need to be carried. Fuel cells can also be air breathing.

Last edited by Graviman; 28th Apr 2011 at 11:47. Reason: Spotted an error in units.
Graviman is offline  
Old 19th Apr 2011, 12:53
  #45 (permalink)  
 
Join Date: Aug 2009
Location: Texas
Age: 64
Posts: 7,131
Received 319 Likes on 204 Posts
Boeing: Boeing Successfully Flies Fuel Cell-Powered Airplane

Though graviman's links would not open for me, I note Boeing's work on fuel cell powered aircraft, in Spain.
Lonewolf_50 is offline  
Old 19th Apr 2011, 20:12
  #46 (permalink)  
 
Join Date: Apr 2003
Location: Vancouver, BC, Canada
Posts: 1,635
Likes: 0
Received 0 Likes on 0 Posts
A couple of MIGHTs

slowrotor & arismount,

The hydrogen fuel cell may be a solution, but it appears that the current discharge rate is not fast enough for the needs of rotorcraft.

As you mention, aircraft can have a higher than normal power requirement during takeoff. One feature of the hydrogen fuel cell that MIGHT be advantageous is that of applying its byproduct (water) to the motor,s coils, for cooling by evaporation. Wick Idea


This MIGHT be the the source of power for very future rotorcraft; Nuclear Power We Might Be Able to Live With


Dave
Dave_Jackson is offline  
Old 20th Apr 2011, 20:17
  #47 (permalink)  
 
Join Date: Aug 2009
Location: Texas
Age: 64
Posts: 7,131
Received 319 Likes on 204 Posts
Dave, about power, and power density estimates.

Is the article you liked to on low energy power generation applying the Blacklight process, or something else? I got a bit confused between reading the article and the links within it, which I had to do, given the article's brevity.
Lonewolf_50 is offline  
Old 21st Apr 2011, 11:58
  #48 (permalink)  
 
Join Date: Nov 2004
Location: Cambridgeshire, UK
Posts: 1,334
Likes: 0
Received 0 Likes on 0 Posts
Dave,

Not pooh-poohing the Focardi-Rossi demonstration, but there are plenty of chemical reasons why introducing hydrogen to nickel might give off excess heat. The nickel could just catalyse a reaction with atmospheric oxygen.
Graviman is offline  
Old 21st Apr 2011, 21:40
  #49 (permalink)  
 
Join Date: Apr 2003
Location: Vancouver, BC, Canada
Posts: 1,635
Likes: 0
Received 0 Likes on 0 Posts
We may be starting to move away from the subject of the Electric Sikorsky. If so Senior Pilot may wish comment.


LoneWolf_50,
However, in response to your question, the following is an e-mail from a person who is much more knowledge on the subject of electrical storage then me.

The BlackLight Process

"I remember being introduced to this page about 2 years ago. I could not corroborate their story, so left it but now after seeing the ECat (energy catalyzer) from Rossi, it seems they are using the same "new" process that everyone is struggling to quantify and describe. Rossi is using Nickel and Hydrogen and says other metals may be used. These guys are using Sodium Hydride and Hydrogen. It all looks very similar and maybe "more than one way to skin a cat". Whatever the outcome, it only looks better and better for risk-free, cheap energy for all."


Dave
Dave_Jackson is offline  
Old 22nd Apr 2011, 15:08
  #50 (permalink)  
 
Join Date: Aug 2009
Location: Texas
Age: 64
Posts: 7,131
Received 319 Likes on 204 Posts
Dave:

Given that the density of electrical power, the volume to weight to stored energy ratios, are critical factors in any electric drive helicopter being commercially viable, I'd guess that this tangent is within the topic we are addressing.

I'll leave it at that, as the processes you linked to look to be in the early stages of development/maturity.
Lonewolf_50 is offline  
Old 21st Jun 2012, 04:40
  #51 (permalink)  
 
Join Date: Apr 2003
Location: Vancouver, BC, Canada
Posts: 1,635
Likes: 0
Received 0 Likes on 0 Posts
In the May/June 2012 issue of Vertiflite, from the head of Sikorsky Innovations;

"Our electric helicopter last year just wasn't ready for prime time. We could have done a flight, but it would have been a stunt. It arguably wouldn't have been safe enough, so we said, 'Let's hold off.'"


Dave

Last edited by Dave_Jackson; 21st Jun 2012 at 04:41.
Dave_Jackson is offline  
Old 21st Jun 2012, 06:12
  #52 (permalink)  
 
Join Date: Dec 2000
Location: midcoast US
Posts: 171
Received 0 Likes on 0 Posts
"Our electric helicopter last year just wasn't ready for prime time. We could have done a flight, but it would have been a stunt. It arguably wouldn't have been safe enough, so we said, 'Let's hold off.'"

I looked at it last year at AirVenture. I'll look for it this year and give a report, if warranted.
rotorfan is offline  
Old 21st Jun 2012, 14:46
  #53 (permalink)  
Thread Starter
 
Join Date: Jul 2003
Location: Port Townsend,WA. USA
Posts: 440
Likes: 0
Received 0 Likes on 0 Posts
So the whole thing is just "Green" marketing?

At least they gave me a free T-Shirt last year at the Airventure tent.
slowrotor is offline  
Old 21st Jun 2012, 20:13
  #54 (permalink)  
 
Join Date: Apr 2003
Location: Vancouver, BC, Canada
Posts: 1,635
Likes: 0
Received 0 Likes on 0 Posts
Lightbulb

slowrotor,

If you want to go 'green' and not wait for batteries to improve, then what about considering a very lightweight Genset?

This is an idea that is being played with.


Dave
Dave_Jackson is offline  
Old 21st Jun 2012, 21:48
  #55 (permalink)  
 
Join Date: Jun 2012
Location: Canada
Posts: 21
Likes: 0
Received 0 Likes on 0 Posts
onetrack,

I have to agree somewhat with your comments about purely electric propulsion systems for autos or aircraft. While purely (nuclear) electric propulsion makes sense for large ships and subs, it is not yet practical for cars or aircraft, due to limits with battery technology. The motor technology is ready, but the batteries are still way short of where they need to be.

In my opinion, the whole emissions-free, electric drivetrain argument also doesn't make sense. At least here in the US, where 60% of electricity is produced by burning coal and another 20% is produced by nuke plants. Your "electric" helo is, in reality, coal or nuclear powered.

Regards,
riff_raff
It's comical how no one seems to realize this. People see electricity as clean energy and give no thought what so ever to how it is being produced, Coal power generates 44% of the US's electricity and 39% of its CO2 emissions. natural gas is no where near as dirty but it still creates CO2. Ironically residents who live near coal power plants are exposed to higher radiation levels than those living near nuclear plants as well.
cbox chip is offline  
Old 22nd Jun 2012, 09:18
  #56 (permalink)  
 
Join Date: Mar 2010
Location: Florida
Posts: 220
Likes: 0
Received 0 Likes on 0 Posts
It's comical how no one seems to realize this. People see electricity as clean energy and give no thought what so ever to how it is being produced
CBOX, try not to let yourself get to the point of throwing the baby out with the bath water. Electricity IS clean energy. What it is generated from is a whole nother issue. Whether you charge a battery with coal or solar cells doesn't change how clean or dirty an electric motor or a battery is.
Back in the recesses of my mind I can hear Orville making your point to Wilbur... "Maybe we shouldn't.....This thing could wind up crashing and hurting somebody."
Or why da Vinci's invention never left the drawing board.... "Forget it. This thing could wind up screwing up the air."

Electric systems need to be developed. Sikorsky Inovations may have said "Lets hold off" but someone else said "Lets go for it!"

Last edited by fly911; 22nd Jun 2012 at 09:20.
fly911 is offline  
Old 22nd Jun 2012, 16:54
  #57 (permalink)  
Thread Starter
 
Join Date: Jul 2003
Location: Port Townsend,WA. USA
Posts: 440
Likes: 0
Received 0 Likes on 0 Posts
"If you want to go 'green' and not wait for batteries to improve, then what about considering a very lightweight Genset?"
Dave


No such thing as "Green". (in my opinion)

Even solar cells are made from huge amounts of coal used to refine the silicon.
(up to 25 times more energy than used to make steel, I think some professor calculated)

A genset design might just add more unneeded weight if you try to connect the main engine with various shafts, etc. I think a very small alternator would be enough and avoid some problems.
slowrotor is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.