Please say it ain't so.

[Dave_Jackson]

• The future cost of oil will drastically increase; due to limited reserves and growing demand. ~ Peak oil; [http://www.lifeaftertheoilcrash.net/]
• Global warming from hydrocarbons will continue to increase; with no current means of stopping it. ~ Dimming the Sun; [http://www.pbs.org/wgbh/nova/sun/]
• Per seat-mile, the helicopter is the most fuel-inefficient mode of transportation there is.

____________________

• Simply improving the rotors, controls or empty weight will be insignificant when compared to the above.
• Any future electric helicopter will have to go back and re-experience the previous seventy years of engine, powertrain and fuel weight reduction.

Can civilian rotorcraft ever be a growth industry?


Depressed

[Agaricus bisporus]

Sure it can.

The growth comes from the continual need to refine and redefine the helo and it's roles.

Social pressures may take a big slice out of charter and to a lesser extent VIP work, but they will never prevent the helicopter from doing what it was designed to do, a role that nothing else can replicate. A jeep is an expensive town runaround, but if you need a mountain rescue it looks cheap, and when the jeep gets stuck...

The only means of transport yet devised that has saved more lives than it has taken? Doesn't that tell us something?

Maybe the purest civil aspects of helo ops may reduce in favour of more quasi-official ones which may or may not leave you filled with a warm, snug feeling, but the future of the beast itself is assured.

Oh, and unless we get on with an urgent new nuclear power plan there'll be no patience either for a battery electric helo in the midst of the 3 day power week we'll all be suffering from by then.

Suggest make hay while sun shines!

[Graviman]

Dave, you're being overly pessimistic again...

The end of the world is nigh!
Or
The voice of reason...

We have a serious fuel crisis looming, but it is just a question of common sense finding a solution. Every square meter of earth receives 1kW/m^2 of sunlight. There is enough coal to last another 200 years. Nuclear fission exists as an interim solution with fusion on the horizon.

Alternately we could collectively bury our heads, continue to ignore concerns about mpg of SUVs (the ones that don't actually go off-highway), and mindlessly ignore the kerosine requirement of passenger jets.

My own view is that us engineers will have to find a practical solution. The first is to convert other viable energy sources into liquid hydrocarbons. Forget all this hydrogen nonsense: all heavy lift rockets use liquid kerosine for stage 1, since it has the highest energy/volume figure (the exception is STS SRBs using ammonium perchlorate and aluminum). Rockets are extremely weight sensitive, so helicopters must be better using easily pumped diesel/kerosine.

However research into methods to improve helicopter aerodynamic efficiency are also a very practical solution. You were championing Independant Root and Tip control for rotor efficiency.

Besides with CO2 induced global warming, i have the feeling we are going to be seeing a lot more helicopters over flooded regions...

Mart

[slowrotor]

Dave,
A guy approached me a while back with a scheme to build an electric powered parachute. That would be about the only aircraft that is less efficient than a helicopter and I told him I thought it probably would not work. Most of the effort in electric aircraft is with very efficient glider like aircraft. Even Boeing is building an electric motorglider.
Anyway, this guy proposed to use ultracapacitors.
Do you have any info on ultracapacitors?

The dimming sun caused by particle pollution is apparently slowing the onset of global warming to some degree. Cheer up!
I saw an advertisement for a large SUV that does 0 to 60 in about 5 sec.
Unbelievable. I was shocked. Nobody seems to care.

[Simon853]

electric powered parachute

That's an interesting idea. If a lightweight photo-electric fabric could be developed it could potentially power itself maybe.

Si

[IFMU]

Originally Posted by slowrotor

Do you have any info on ultracapacitors?

I think that's the secret ingredient in the 500 mpg carburator.

-- IFMU

[chuks]

Funny you should mention this but...

The recent boom in SUVs, especially in the States, is really amazing for a display of the 'head in sand' approach to life practised by 'most people' and their politicians. Check out your average motorcade for lots of seriously large and shiny black wotsits, copied by the general public with, seemingly, no thought to what the fuel costs to run these monsters.

Ford, was it not, was just boasting about the biggest and heaviest SUV ever, as if this meant progress. A quirk in US legislation has these monsters set aside from the Corporate Average Fuel Economy (CAFE) legislation, since they are classed as Utility Vehicles rather than private ones. Nice one, that! This has gone ignored just to keep the voters happy while they burn their way through the hydrocarbons like improvident children.

Then the oil companies happily jack up the pump prices without regard to the real cost increase per gallon, again with nothing much done by the politicians. I am sure this has nothing to do with the cash coming in as political contributions. Or the contributions in kind, either. Big Oil just has to stand in line when it wants something in a democracy, right?

Meanwhile, though, if you are in serious trouble, needing a quick trip to the hospital or hoisting out of a river, say, can you come up with an alternative to the helicopter? I would bet that the future for utility-type air vehicles is one of the most secure sectors to be working in. Air tours and such might take a hit but EMS and SAR will always be with us for the foreseeable future, so cheer up! When the end of the world is shown on the evening news the view will be coming from a news helicopter.

Given that I am F/W I wonder just where I can find a perch in all of this. I suspect that the mass tourism market may just go down like a big house of cards, when 'the great unwashed' all decide to stay home and grill weenies instead of flying off to Maui to do the same if they have to pay more than $99 per head. A lot of F/W is pretty disposable stuff in terms of its real necessity.

[Head Turner]

For the car builders and the fuel providers their incentives are not and never will be the consideration of the planet BUT profit as upheld by the president himself who backed the American industry not to cut polution levels. So, where do we go from here.
The motor industry is a mamoth holding hands with the oil giants therefore should a wonder fue/oill be developed that bypassed the oil boys, I would suspect that some purchased legislation would be forced through to ensure that the newcomer with the bright idea would NOT succeed.
More efficient rotor technology coupled with an equal increase in engine efficiency is the obvious goal for the rotorcraft industry and it is apparent that there are those who are succeeding slowly but surely and it's great that there are these people working for the overall benefit of those who need helicopters versus the damage to the environment.

[Graviman]

SlowRotor,

I did my project for the guy behind the Boeing project, but turned down a pHd - he now runs Intelligent Energy, while i test/stress/design off-highway behemoths...

Beoing Electric Demona

There is plenty on google, but your guys project is sounds feasible enough.
eg. http://www.maxwell.com/ultracapacitors/index.html
Traction batteries also offer very good power to weight. The down side is that there would be absolutely no range, and it would need recharging before every flight.

Originally Posted by SlowRotor

The dimming sun caused by particle pollution is apparently slowing the onset of global warming to some degree.

The scary thing is that diesel catalysts, amongst other engine particulate reductions, will reduced this effect. This in total could be by as much as 20%, so predictions for global warming have actually all been optimistic.

Mart

Edit: clarification - thanks Flying Squirrel.

[TheFlyingSquirrel]

Originally Posted by Graviman

The scary thing is that diesel catalysts have now reduced this effect by 20%, which is accelerating global warming more than had been realised.
Mart

Can you provide a link online to bolster this statement ? Not questioning your comment, just interested.

[slowrotor]

Mart,
The Maxwell ultracapacitor site is a little vague about total stored energy.Can capacitors store more energy than lithium batteries per pound? Has anybody built a car or anything big with ultracapacitors?
I think fuel cells are bit far off for a couple reasons: Hydrogen is not a naturally available fuel and is difficult to store and handle. Secondly, fuel cells are expensive.
The safety of hydrogen is not a problem in my view. The Hindenberg fire was shown to be caused by flammable hull fabric, not the hydrogen as most believe. Actually, hydrogen would be good for an airship, no problem with storage in the gas bag.

Edit:
I did a google search and found ultracapacitors still have low specific energy as compared with current lithium batteries. However a new nanogate capacitor shows promise with much higher power. Stay tuned for this product.

[Graviman]

Originally Posted by Flying Squirrel

Can you provide a link online to bolster this statement ?

Happy to help, Flying Squirrel. The 20% assumes that the majority of particulates are caused by diesel emissions which oxidation catalysts are designed to remove (Tier 4 / Euro 4 emission requirements). In practice this figure will be lower, although there is a general drive towards lower particulate emissions from all engines. It is still cause for concern.

BBC Horizon: Global Dimming

SlowRotor,

I came to the same conclusion about fuel cells and hydrogen, which is why i chose not to further my studies at that time (agreed about the safety of hydrogen too). Eventually the chemistry will allow direct conversion of hydrocarbons to electrical power, then they will "take off". Methanol fuel cells use copper as a catalyst, and i even have my own concept for heavier HCs (but this isn't really the time or place to expand on that).

Regarding Ultracapacitors, they were pinoeered by Toyota (from memory) to expand the performance of their hybrid vehicles. Toyota have played around with some clever hybrid shunt transmissions for many years. Honda chose to stick with LiMH for their hybrids, and for my money offer a better solution.

The real constraint to your guy's project is going to be keeping the cost of batteries and motor down. For this reason alone you are better sticking with LiMH technology, since it is an already mature technology. You will need to get an arrangement of cells that deliver the best power/weight, by keeping cell resistance at least as low as motor resistance. Don't forget to allow cooling of the cells, since they will get warm on take-off power. Once airborn the guy can just thermal, and in fact weight is actually an advantage on a strong thermic day (faster average speeds).

Mart

[Dave_Jackson]

China is already the world's second biggest user of oil. It is expected to double its consumption within the next ten years. Then there is India, etc. etc.

It is reported that on some days in Beijing the pollution is already so bad that it is impossible to see more than a few yards. Perhaps the world will become aware of this growing problem, if hundreds of millions are ready to watch Olympic soccer but the cameras are unable to find the field.

_______________________

Agaricus bisporus:
IMHO, there will still be some valid civilian uses for helicopters. However, the usage may not grow. This will mean that any new product development costs must be amortized over a small number of craft.


Slowrotor;
An idea that was kicked around was related to multi-function components. The idea was to make the fuselage serve as; aerodynamic skin, structural frame and super-capacitor. God knows what happens when lightening strikes. The CNC controller had an 'explosion' last week when I wired a capacitor in the wrong way around.


TheFlyingSquirrel;
Mart's remark relates to 'Dimming the Sun'; [http://www.pbs.org/wgbh/nova/sun/]
It was covered in a very interesting NOVA program a couple of days ago.

_________________________

Current rotorcraft have slowly worked their way up to an empty-weight to payload ratio of 50/50. The initial implementation of electric power will return the ratio back to around 80/20.

In addition, the conceptual design objectives of electric rotorcraft will be very different from that of current helicopters. The emphasis will be directed at just keeping the craft off the ground for a reasonable period of time.

[Graviman]

Originally Posted by Dave Jackson

In addition, the conceptual design objectives of electric rotorcraft will be very different from that of current helicopters. The emphasis will be directed at just keeping the craft off the ground for a reasonable period of time.

Dave, i've searched for a way to justify electric or hybrid helicopters and reached a final conclusion: you just can't!

The problem is that they are way too aerodynamically inefficient to be powered by anything other than IC engines. Future fuel cells may well deliver, but we are just not there yet ( believe me if i had the time/cash...). I was amazed when the R22 had a "glide slope" about the same as a parachute canopy, ie pretty lousy. The Demona was chosen for the I.E./Boeing project since it has a glide slope of about 26:1 (from memory), so you can cruise on the cell with batteries only required for takeoff power.

You had a good idea with Independant Root and Tip control. To my mind this is the way forward with helicopter fuel consumption. I genuinely believe that HCs like cetane are still the way to go for helicopters, whatever their original energy source. Concentrate on optimising the rotor AOA, but accept that you have to use an aerofoil that doesn't suffer in reverse flow. This then really justifies your symmetric concepts, especially at higher speeds.

Mart

[Dave_Jackson]

An Idea.

It gives the participants the opportunity to initiate electric rotorcraft flight, plus make $20,000.00 at the same time.

The objective is simply that of; using electric power, hovering one man for one minute, and momentarily achieving an elevation of 3 meters.



The Craft:

A pair of large coaxial rotors with extremely low disk loading.
All four blades are constructed as capacitors.
A charger/motor is located between the two rotors.

The Flight:

While the craft and pilot are sitting on the ground, the pilot generates sufficient electricity to fully charge the blades.
He then switches the charger into a motor and lifts off for one minute.

The Money:

The American Helicopter Society Igor I. Sikorsky Human Powered Helicopter Competition
http://www.vtol.org/awards/hph.html

[slowrotor]

Dave,
Did you notice the rule that disallows stored energy of any kind?

Back to the topic of saving the world from the energy crunch and global warming. Here is my thought:
We could do more for the world if we used our aero knowledge to improve surface vehicles by designing lighter cars. But the trend is heavier cars.
The danger of driving a 500 lb car is a big drawback. So I think it may be required that new ideas come from the aero side because we can fly light designs with little concern of a collision imbalance based on mass.
The freedom to design new aircraft could help lead the world.
Look at how Paul McCready continues to push the limits of efficiency. His craft are mostly impractical but he has shown what is possible. There is no reason for the rest of us to give up.

[Dave_Jackson]

slowrotor,

Yes but notice the exception. "Rotating aerodynamic components, such as rotor blades, used for lift and/or control are exempt from consideration as energy storing devices."

It does not distinguish between electrical energy and the energy of rotational inertia.
_____________________________

Reducing the weight and improving the design etc. will make for a better rotorcraft. However, after having done this, the next most significant step in popularizing the craft is that of 'mass' production.

This craft would not see the marketplace for 10 to 20 years and in 10 to 20 years the 'masses' are not going to put up with anything that pollutes. In addition, they are not going to be able to afford anything that pollutes.

IMO, carbon fuelled engines will go the way of the dodo bird. Paul McCready's work is one farsighted step on the road toward electric propulsion.

So is taking $20,000.00 from Sikorsky.

[slowrotor]

Dave,
Paul McCready is offering a $10,000 prize for the first animal powered aircraft.(I am not making this up)
I have a little pomeranian that has a pretty high energy level and weighs 7 lb.
Hmmm.

[HUDAT]

What about rotorcraft using Hydrogen - fuelled engines?

I'm not up with this, but seem to recall several newsitems over the past few years indicating that this is becoming a viable proposition at least for cars etc.
Anybody understand the issues with hydrogen?

[Graviman]

Originally Posted by Dave Jackson

Paul McCready's work is one farsighted step on the road toward electric propulsion.

Dave, could you put a link to this stuff?

Originally Posted by HUDAT

Anybody understand the issues with hydrogen?

It just doesn't work, Hudat, despite having attained a "trendy" image. Hydrogen has the best energy/mass, but the worst energy/volume. To improve energy/volume you use pressurised containment or carbon entrapment, this then gives it the worst energy/mass.

Liquid hydrocarbons are good precisely because they are liquid, and easily transported/pumped. I am not just saying that because of my background in powertrain design analysis. Hydrogen doesn't lubricate mechanical components the way for example diesel or kerosine does, which leads to very high wear rates.

From the thermodynamic view the turbo-diesel engine will always outperform other ICs since you can inject fuel during combustion. I think of TDI as more a reciprocating turbine combustion chamber, which indicates its future potential in helicopters. At this moment diesels are beginning to show their performance, and don't be suprised if a diesel wins LeMans this year:

Ricardo modified JCB 444 Diesel and Audi R10 TDI LeMans Series Racer

HC fuel cells will come, but they will not be competitive to the IC for quite some time. In the interim i would be far happier if (for example) the US implemented a Tier 4 emission diesel car initiative - my VW regularly gets 50mpg...

Mart