Electric Air craft?

[Viv]

As part of my ongoing development work I keep an eye on propulsion systems in general and specifically for new trends, what I am seeing is a strong move towards practical electrical drive systems for small airframes, this is not only for small UAV airframes but larger man capable airframes too.

Don't just think batteries though, fuel cells are catching up very fast too along with improvements in flexible solar cell technology and efficiency.

have a look at this link http://www.gizmag.com/yuneec-e430-elect ... aft/12036/ this is a small light aircraft that will fly for 2.5 hours on a single charge and takes 3 hours or so to recharge, claimed I add but heres the thing it only is costing $89k usd! thats cheap and its going to have lower maintenance costs than a comparable piston engine light aircraft.

Is this the future of small low cost aviation? could be? certainly I am finding it very interesting to consider with future travel needs

Viv

[Viv]

As an update to this, here is another article including a video

youtube
http://www.youtube.com/watch?v=IGhUCOvE ... r_embedded

The register
http://www.reghardware.co.uk/2009/06/26/yuneec_e430/

Viv

[Viv]

This is another interesting electrically powered air craft, about the same total horse power but a slightly different overall range

http://www.wired.com/autopia/2009/06/solar-impulse/

Viv

[Viv]

Another link and a better photo of the proposed round the world electric flyer

http://news.cnet.com/8301-11386_3-10274 ... 47-1_3-0-5

Viv

[GRIM]

Hey Viv, nice post ,
QUOTE
"Despite a wingspan equal to that of a Boeing 747, the Solar Impulse weighs only around 1.7 tons, about the same as an average car. More than 12,000 solar cells mounted on the wing supply renewable solar energy to the four 10-horsepower electric motors. During the day, the solar panels charge the plane's lithium polymer batteries, allowing it to fly at night."

40 hp , WOW , This is one to keep your eye on, flying at sufficient altitude to gaurantee strong sunlight , this looks really good ,

[Viv]

Hi Grim

I like these electric aircraft as they are developing so fast, only a short while ago there were none at all and now we have some serious contenders for commercial sales and record breaking flights, the specifications look good to me and they seem to have done their planning for the team of pilots and the changeover stops, 40 hp spread across four motors gives them some system redundancy as well.

The market for 50 lbs thrust engines in UAVs was pretty interesting the next bracket up for manned airframes but I seriously doubt now that we will see any new combustion engines making it big as these electric drives will outpace them so quickly, add a fuel cell to the batteries and printable solar cell technology to lower the weight and even the bigger airframes will turn over to electric drives.

Good luck to them

Viv

[GRIM]

Hi Viv ,
Yes I agree completely , at the model club there are a few people with "foamies" the airfames are a marvel with their carbon spars and all ,
But the real revolution is in the electrics, the brushless motors are REAL 3 PHASE MOTORS , with variable frequency drives smaller than a credit card , and the batteries are not much bigger !!, this level of technology was not available "to the public" even 10 years ago, and as we know, what is available today is basically obsolete allready compared to "what is in the works"

I have installed a lot of industrial 3 phase motors with VFD from 1 hp to 150 hp , they are dinosaurs ,

Great stuff

[Viv]

Hi Grim

Thats exactly the point really, the level and speed of development is fueling this new application in propulsion, I did a lot of work back in the 90s when spiral vector phase theory first came out from the Japanese engineer Yamamura http://www.geocities.jp/ps_dictionary/y ... /book2.htm this was really huge step forward in motor speed control and design, I designed the first variable speed woodturning lathe for a company back in England from that work.

The size of the converters and the fact that we had to rewind the motors meant every thing was over sized, the modern controllers have astounding performance and power handling in comparison and now the motors are designed from the ground up to work with spiral vector controllers they have shrunk and reduced the heating problems as well.

Viv

[Viv]

Just as an addition to this topic, I mentioned fuel cells the other day and maybe I should have given a few more details as to what I was refering too and how big they are, this is a low power design but for a small drone it does not have to be that big, also RC flyers could use some thing like this to

article
http://www.technologyreview.com/energy/22854/?nlid=2143

There are much bigger units and there is a 5 kw military generator pack in production, fuel cell technology is experiencing some real development and is a key game changer for extended range electrical drives in airframes.

Viv

[Viv]

I had not thought things had advanced enough for a manned fuel cell powered flight but seems I was wrong

http://www.physorg.com/news166191289.html

Viv

[PyroJoe]

Like the progress of the electrics. One plus for the pulse jets (if setup to do so) is surviving constant EMP strikes. Maybe a small niche.

Strange that an EMP can be delivered from a shell fired out of a cannon these days.

[Viv]

Hi Joe

Yes EMP is always a problem in defense electronics and the source of EMP is getting smaller and more likely to turn up in field shall we say

This is another nice developing technology that will be a game changer http://www.af.mil/news/story.asp?id=123153093 imagine printing your solar cells directly on to the skin of the airframe

Viv

[Viv]

Yet another bit of electric propulsion news this time from Wired magazine and a nice article on an ultra light, this actually looks like a well engineered system and may well gain some traction in the market.

Clearly the old 50 pound thrust market in the UAV market space that was catered to by micro turbines and the odd pulse jet is going to be overrun by these types of off the shelf plug and play systems.

http://www.wired.com/autopia/2009/07/ne ... c-airplane

Viv

[GRIM]

Hey Viv , That really is fantastic, what a neat motor , 22 kw almost 30 hp in such a small package ,
surprised me how much racket the prop makes, room for improvement there I would say ,
would that be fixed pitch ?

That particular instalation has the batteries in a less than ideal location (WRT streamlined) , maybe its a centre of gravity thing , , or maybe they get hot , but I can see that motor would be really easy to fit in a very streamlined nose cone or wing mounted pods , or just about anywhere ,

Clearly the old 50 pound thrust market in the UAV market space that was catered to by micro turbines and the odd pulse jet is going to be overrun by these types of off the shelf plug and play systems.

Yep reckon its all just a matter of time ,

[Viv]

Hi Grim

Yes I was very impressed by the power to size ratio of that motor, I would still be pleased if it was only 20 hp for that package, I wonder what the duty cycle is though? but all in all its frontal area is tiny compared to a regular gas engine, and yes I agree, the batteries scream out for a custom packaging job to be done to reduce their frontal area to match that of the motor.

A nice spinner would help to I guess

Viv