FLYING with electricity

[RoughRider]

New article about eflight on the EAA site. Basics about motor topographies, controllers and lithium batt tech, including predictions for the future such as pack energy densities "...365 wh/kg is expected in the next couple of years":
http://www.eaa.org/experimenter/articles/2010-05_electric.asp

tks
lLok

no, i mean this one here

 

[Lock]

Ah... thats the motor from Lange Aviation for the Antares glider (pics above):
http://www.lange-aviation.com/htm/english/products/antares_20e/propulsion.html

The patented propulsion system was developed especially for the Antares 20E and is the heart of the concept.
Lightweight environmentally friendly batteries with high performance, a brushless 42 kW external rotor electric motor, new power electronics and a large slowly rotating propeller were developed into one system and tailored especially for the Antares 20E into an optimized configuration. For the first time, a complete propulsion system has been developed exclusively for one motorglider.
The results are convincing: The Antares 20E combines a high climb rate (approx. 4.4 m/s / 866 ft/min during takeoff) with a very high attainable climb altitude (approximately 3000 m / 9850 ft in calm air) and very low noise emission.
Great performance is only one aspect of this new propulsion system, amongst the others one finds impressive motor parameters, high system reliability, and intuitive, blind controllable and highly responsive motor controls.

The motor
Named EM42, the motor of the Antares 20E has been developed especially for Lange Aviation, and it is currently the only EASA certified electric aircraft motor in existence. It is an brushless fixed-shaft electric motor running on DC-DC current. Running at 190 - 288V, and pulling up to 160A, the 42kW motor can deliver maximum torque over a wide RPM range. With a total efficiency of 90% and a maximum torque of 216 Nm, the motor is exceptional not only within aviation.

By using relatively few high quality components, risk of failure is minimized. The Antares 20E propulsion system causes very little vibration. This avoids vibration related problems, thereby increasing total system reliability.

Furthermore, all electrical components are attached to the non-moving part of the motor. The motor itself contains only 4 parts (2 ball bearings and 2 sealing rings) which are subject to wear. The TBO for the motor is 900 hrs. The simple mechanics of the motor results in simple and low cost maintenance with very long maintenance intervals. Maintenance consists of exchanging the two sealing rings, and it must be performed every 200 hours of motor time or every 10 years, whichever happens first.

Engine Data
Motor DC/DC brushless
Power 42 kW / 57 hp
Revolutions 1500 rev/min
Maximum Revolutions 1700 rev/min

I'll guess ya would have to throw a LOT of money at Lange to get one of those...
Lock

 

[Lock]

These folks seem to be making their own motors... controllers too?
http://www.eledriveco.eu/

Looks like their controller is water/fluid cooled:
View attachment Ele-DriveCo.bmp

Kinda loud prop, but their machine is a big two-seater:
http://www.youtube.com/watch?v=7BH0Fs8SbIY
[youtube]7BH0Fs8SbIY[/youtube]

- max power of the motor 25 kW,
- max thrust 120 kG
- Li-Po battery with BMS - 7 kWh
- flying time up to 1 hour (1 person)
- total weight of the 2 person trike 130-148 kg (depending on the equipment as sort of wheels, shock absorbers etc)

Coupla other of their motors:

No details on their site for their motors but they look "big"... Nameplate on the second motor says PM and 104kg... maybe 500A... hard to make out. They also offer to convert a Polaris Sportsman 500 ATV

Parametrs after the conversion:
- nominal power 14.9 kW (20.2 Hp)
- max power 30 kW (40.8 Hp) - excellent accelerating
- modern lithium polymer batterypack (7kWh)
- easy chargable (charging from standard outlet 230V)
- max speed 70 kmh
- regenerative braking (while braking the battery is charged)
- up to 3 hours of fun of electricity cost less than 1 Euro

tks
lLoK

 

[Lock]

someone with some aeronautical expertise tell me why you couldn't take something like this

and then add two of those colossus 12kw motors driving each their own propeller like those nice folding jobs our new friend has on his. house all the batteries and electronics in that center enclosure instead of the jet engine that they plan on putting in there. better yet have one of each and have them be interchangable. I wonder how much weight would be added to throw some of that nano solar film over the top of the whole thing, it could add range and allow the thing to charge in the sun when you are not using it.

They just posted another Youtube video (CAUTION - Noisy stinky vehicle. Some might be offended.):
http://www.youtube.com/watch?v=LPIPxl_eS4k
[youtube]LPIPxl_eS4k[/youtube]
tks
loCk

 

[only1jake]

tut tut tut... They didn't even get it in the air I was excited watching that ahah. Nice glider/plane/whatever that thing is called. Would be great to see that flying I would think.

















... Only is it was electric

 

[Jeremy Harris]

Some neat ideas in that flying wing design, but a couple of major design flaws that these guys really should have picked up, given the great job they've made of engineering the thing.

The wing area is fairly modest, so for a low take off speed the wing angle of attack will have to be pretty high. The static AoA with the nose wheel down looks very low, and they don't have any adequate means of lifting the nose wheel on the take off run to get the AoA up (if the wing has elevons then they are way too far forward of the rear wheel to have any useful effect). The second problem is that they seem to be using weight shift roll control, but haven't picked up on the fact that this will have a major impact on ground steering with a bicycle undercarriage layout. With any sort of slight crosswind they will need to keep a wing slightly down to keep the aerodynamic vectors pointing the right way, yet putting a wing down will cause a lean-steer over-reaction, which is exactly what they don't need.

It also looks to be a bit under-powered, with a bit more static/low speed thrust the ground control problems might be lessened, as they may then be able to accelerate up to aerodynamic control speed before losing ground directional control.

Jeremy

 

[Miles]

Jeremy,

What is the reason for the anhedral sections on the ends of the wings? They need it to be less stable in roll..?

 

[Jeremy Harris]

As it seems to be using weight shift roll control, then yes, I would think that the anhedral is there in part for that, flexwing microlights have anhedral for the same reason. The other reason may be just practical, in that they wanted to have the roll angle on the ground limited by tip skids.

Jeremy

 

[liveforphysics]

Jeremy,

What is the reason for the anhedral sections on the ends of the wings? They need it to be less stable in roll..?

With an RC plane that has a steep dihedral, flying upside down (making it anhedral) makes a small alerion input have a huge effect. Maybe they thought they could use smaller control surfaces and increase wing rigidity because of it.

If that was my craft that gets flown by laying on top of the wing, I would have put a bunch of dihedral in it, and shot down a couple of roller blade wheels on air foil shaped carbon fiber struts on the tips of each wing. Mount a plate on the end of them, and the lift would improve enough you could choke up on the wing length a bit to help make up for the increased drag. I'm sure overall it would be a signifigantly higher drag wing though, but hey, thrust is cheap! They just didn't use nearly enough.

 

[bzhwindtalker]

It has such a weird layout because it's from a manga

Nausicaa:

 

[Jeremy Harris]

Dihedral is a very mixed blessing. It adds to roll stability, but generates a massive yaw/roll couple, so that yawing creates a lot of roll. Sometimes this is a good thing, several two axis ultralights (like the original Quicksilver) took advantage of this secondary effect to eliminate direct roll control altogether. It's not at all helpful when trying to control roll without ailerons, though, not is it helpful on a flying wing design with marginal lateral stability and poor yaw control. If you are relying on weight shift roll control, as I suspect this thing does, then you need anhedral to increase the sensitivity to weight shift. Of course, anhedral brings it's own set of compromises, including poor lateral stability.

Take a look at the Wright Flyer. The Wrights used partial weight shift roll control and had to incorporate anhedral to make it work. One consequence was that the Flyer was a complete bitch to fly - I tried to fly the simulator at a US show a few years ago and the damn thing seemed unstable in all three axes! I take my hat off to those guys, as they flew it better than I did, with no one to teach them how to fly.

Jeremy

 

[Miles]

As it seems to be using weight shift roll control, then yes, I would think that the anhedral is there in part for that, flexwing microlights have anhedral for the same reason. The other reason may be just practical, in that they wanted to have the roll angle on the ground limited by tip skids.

Thanks Jeremy.

I found it difficult to imagine controlling it at take-off speeds....

 

[whatever]

just some random thoughts about using brushless dc motors for an aircraft engine
begin with this new design windgen ( flodesign company ma, usa)

http://www.youtube.com/watch?v=WB5CawKfE2M
they claim 3 to 4 times increase in capturing wind energy ( dont laugh just yet!)
they are using jet engine flow design techniques, there are new design jet engines using basically the same setup
as per pic below ( note the white section is genuine, the rear of motor has been rendered in)

Finally if you adjust an ordinary water hose nosel, you can get large increase in the force of the hose pushing against your hand, buy adjusting how the water exits the hose ( maybe not relevant but same principle to increase thrust).
So the idea is this ( who knows if it would work or not!)
use the windflo design windgen turbine as a basis for an aircraft engine, assuming that it would also act as an efficient thrust motor where the blades are being turned by an elelctric motor. Incorporate into the design aspects of aircraft jet engines ( I'm not sure if there would be any good reasons for trying this, though im guessing compressing the airflow, then expanding it might only be useful where a fuel is being ignited........no idea really on that).
Earlier in this thread someone posted a link to ultralight electric powered craft, it is using the fisher paykel wasing machine motors, they are making metal components to replace the plastic sections, and assume using neodymium mags on the fp rotors), not sure if anyone picked up on that.
So the fp ( fisher paykel) motors are probably a good place to start experimenting with. Though very small dc motors say from computer fans, might also be useful for doing small scale experiments with increasing thrust.
It would be possible to put a series of fp motors on an axle and get very high power motor.
Finally back to the water hose idea, maybe a very small motor and copy how a water hose increases thrust might be an interesting place to start. Its very unlikely I'll do any experimenting with these ideas but thought I would throw it in the mix.

 

[whatever]

heres a closup pic from someones previous link showing fisher paykel motor being used in ultralight aircraft,
run one of these with a xie cheng controller no probs.

 

[Lock]

heres a closup pic from someones previous link showing fisher paykel motor being used in ultralight aircraft, run one of these with a xie cheng controller no probs.

Pretty sure that's the back-side of one of Dr.Ecks motors seen earlier in this thread...

On the subject of ducted props this water prop is an "outrunner" sorta design with coils in the outer shroud:

This pic is of an earlier proof-of-concept... a later version did away with the center hub all together... just the blades mounted to the outer ring. I believe this design considers weeds in the water (a way to shed them effectively) but might be more efficient? Perhaps a similar approach to a ducted air prop might be more eff as well... Heck of a big bearing though... Maybe the magnets could be used to "maglev" the prop for zero friction...

If ya follow that link for the pic, there's lots more info there about ducted air props (German language)
tks
Lock

 

[Miles]

Pretty sure that's the back-side of one of Dr.Ecks motors seen earlier in this thread...

Looks like it. Not flat wound, though...

 

[Lock]

Interesting... lots of tappity tap here about mod'ing Fisher Paykel motors in the past but I can't recall a pic... so here:

Dunno if FP have had diff. models/versions of motors, but again, pretty sure that pic above is mislabeled.The controller looks like the Flytec controller also:

tks
loCk

 

[Lock]

STILL waiting to see pricing for Yuneec's E-PAC system, now overdue as they were earlier suggesting first deliveries in January/February but no word since.
Lock

Meanwhile, more eye-candy:
http://yuneeccouk.site.securepod.com/PowerMotor.html

Available in 4 different power outputs 10, 20, 40 and 60Kw and 2 different speeds 2,000 and 2,400rpm for the 10 and 20Kw, the power drive range consists of matched motors and controllers and matched battery and charger units.

tks
loCk

 

[Lock]

just some random thoughts about using brushless dc motors for an aircraft engine
begin with this new design windgen ( flodesign company ma, usa)

http://www.youtube.com/watch?v=WB5CawKfE2M
they claim 3 to 4 times increase in capturing wind energy ( dont laugh just yet!)

More stuff not to laugh at maybe... work that mimics the bumpy leading edges of whale fins:
http://www.whalepower.com/drupal/

The Science
Major discoveries always come with a story: Newton had his apple, Archimedes had his bath tub, and Dr. Frank E. Fish, while shopping for a gift, examined a sculpture of a humpback whale in a shop and issued a fatefully inaccurate observation: “Look at that. The sculptor put the bumps on the wrong side of the flipper.”

The shop manager quickly set him straight. She knew the sculptor's work and that the sculptor knew humpbacks: That’s where the bumps should be. A quick check and Frank was convinced the artist got it right. But if the artist was right then at least part of the science of fluid dynamics was wrong. How could that be?

Concept applied here:
http://www.enviranorth.com/

tks
loCk

 

[whatever]

I've been researching building an electric ultralight. I'm really just fishing to see if any other people out there are working on doing similar, maybe one day a section on esforum dedicated to electric flying will emerge

 

[Jeremy Harris]

This is the section on ES for electric flying, it's why the section title is "Electric Aircraft"................

There seem to be an increasing number of electric ultralights/microlights around now. In some ways, the current state of electric system performance is best matched to a low power demand, low wing loading aircraft like an ultralight, particularly a low drag one with good glide performance, where the electric motor could be used as a means of getting airborne and then using some augmentation from conventional soaring to reduce the total energy requirement.

A friend has been working on an electrically powered self-launching ultralight glider a for a while now. That really seems to be a good way to go.

Jeremy

 

[whatever]

whoops didn't realise es forum had flying section even though I posted in it!
Swift hanglider prototype #2 from 1991 pics in my previous post show some closeup details, was sort of a teaser to see if anyone else out there was trying to 'nut out' the internal workings of the swift. Seems there has been very little change since the original design, Ilan Kroo ( and his students) did one heck of a job on designing it.
Aerianne ( belgium) are still making it but they have been making changes to the models mainly in the cockpit fairing, but a few other changes also, but the original wing design has really stood up to the test of time.
Anyone researching electric ultralights doesn't have to reinvent the wheel, progress beyond the swift design seems to be concentrated in uav ( unmanned aerial vehicle) designs.........thats where the bucks are........how to use a electric ( or other) ultralight to kill people is where the big funding is..........says alot about how governments think..........

 

[Jeremy Harris]

There are a couple of Swifts flying here fitted with small paramotor engines and I know that there is one chap in Scotland who has been working on an electric version for a couple of years, but I've not hear anything lately. There is an Alatus ultralight glider flying, with an electric motor for launch and sustain, it's one of the aircraft that a friend is working on (he's the UK agent for the Alatus).

The drive seems to have gone from the ultralight movement, though. Our equivalent of ultralights, microlights, are now really make-believe light aircraft, that bear little or no resemblance to the minimal flying machines that I was first attracted to years ago. Like everything novel and fun, it's gone up-market and been hit by regulation, a sure fire way to kill innovation.

Jeremy

 

[AussieJester]

That is a monster prop :-|

KiM