Electric Powered - High Performance Design

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Christian Moreton

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May 21, 2020
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Tony have a look at this clip. I think it is another great way to show what I think electric is for. Situations where you are looking for extremely low latency reaction time because the maneuvers you are doing require a delicate touch and perfectly even responsive power. IMO Jet turbine is perfect for the kind of flying you want to do. If you want to push the envalope in aerobatics, start to experiment with multi-rotor manned flight for air shows etc, electric has all the benefits. Electric is all about the fact that it's not an engine converting fuel into energy and energy into power, it's a direct application of high torque power for not very long. Which some really want.

I'm looking at grabbing 2 of these motors for my ultralight.

 
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Tony Williams

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May 10, 2020
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Maybe your wife could tow a generator behind the Motorhome to charge the zero emission plane.
Then only a single seater would be enough?
I’m thinking it would be easier to rent a BFDG - big diesel generator at the airport.
 

Christian Moreton

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I’m thinking it would be easier to rent a BFDG - big diesel generator at the airport.
Of if you had a few planes, would make sense to get a tesla battery, that buys power sustainably from wind, or low demand time of day etc.. stores it in high capacity, high C cels, that can quickly dump all the DC current direct into the plane that you want. Could get a full charge in about 40 min.
 

Tony Williams

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The empty weight of the new Diamond DA-62, built in Carbon Fiber, weighs 3,461 lbs. I’m going to guess that there is well over 1000 pounds of motors, interior, etc. so, maybe that airframe weighs 2400 pounds?

Look at the fantastic place to put battery cells between those great looking spars!

709BA7D5-8B30-4EAA-A5F5-8D81E50196CE.png71079B66-7F5C-49EB-B539-55D0D6A16353.png
 

Christian Moreton

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Those large cavities make me think that what we are looking for in power storage should be very long, mostly air filled, air gap capacitors. So it would feel light as pine wood, but have power storage to weight comparable to gasoline. Some sort of Nano aerogel, graphene supercapacitor.
 

Tony Williams

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Those large cavities make me think that what we are looking for in power storage should be very long, mostly air filled, air gap capacitors. So it would feel light as pine wood, but have power storage to weight comparable to gasoline. Some sort of Nano aerogel, graphene supercapacitor.
Well, you could use anything, but I’m going to use lithium cells of the 21mm x 70mm cylindrical size. They would fit in an arrangement like that quite well.
 

sming

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Apr 10, 2019
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Well, you could use anything, but I’m going to use lithium cells of the 21mm x 70mm cylindrical size. They would fit in an arrangement like that quite well.
In a project like this, you need a structural battery idealy? I wonder what kind of strength you could get by using all those tiny tubes of aluminium as some kind of honeycomb structure, containing electrons :)
You would need to master spot welding aluminium.
I also imagine you should choose an airfoil sized to put a maximum of these cells inside the wing?
 

Christian Moreton

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In a project like this, you need a structural battery idealy? I wonder what kind of strength you could get by using all those tiny tubes of aluminium as some kind of honeycomb structure, containing electrons :)
You would need to master spot welding aluminium.
I also imagine you should choose an airfoil sized to put a maximum of these cells inside the wing?
Also I've been asking around about mixing battery chemistry for increased performance, and so far nobody has any real objection to it. Which I mean that an electric aircraft could have a composite power supply. Starting with Super Caps that are the front line for supply, a few seconds of pep power on demand for quick acceleration to give that push back in the seat thrill. Then Lithium Ion for the bulk of power storage as that has the best energy density. Max power from them should be adequate takeoff, but not super thrilling. And behind that you could have an emergency power Li-Po for say 5 minutes of power in case of Li-ion fire. And hopefully we get gas turbine range extenders for cruising cross country and to recharge plane on ground if no power sources.
 

Tony Williams

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Tony Williams

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May 10, 2020
Messages
113
In a project like this, you need a structural battery idealy? I wonder what kind of strength you could get by using all those tiny tubes of aluminium as some kind of honeycomb structure, containing electrons :)
You would need to master spot welding aluminium.
I also imagine you should choose an airfoil sized to put a maximum of these cells inside the wing?
Yes, I’ve explored known wings, like the Swiss P16 / LearJet 35/36 wing and now Piaggio wing. Since we know exactly how much fuel they hold, and how much that fuel weighs, it’s pretty straight forward to determine how many battery cells will fit (at 1kWh / 10 pounds up to about 1.25kWh / 12.5 pounds per US gallon).

You can’t weld the tubes on the cells, since they are actually part of the battery.
 
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Tony Williams

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Also I've been asking around about mixing battery chemistry for increased performance, and so far nobody has any real objection to it. Which I mean that an electric aircraft could have a composite power supply. Starting with Super Caps that are the front line for supply, a few seconds of pep power on demand for quick acceleration to give that push back in the seat thrill. Then Lithium Ion for the bulk of power storage as that has the best energy density. Max power from them should be adequate takeoff, but not super thrilling. And behind that you could have an emergency power Li-Po for say 5 minutes of power in case of Li-ion fire. And hopefully we get gas turbine range extenders for cruising cross country and to recharge plane on ground if no power sources.
The lithium cells have instant power. There’s no advantage with capacitors.

Capacitors are not “energy storage”.

If there’s going to be a turbine “range extender”, you probably should just get rid of the batteries and power the plane with Jet-A. That’s a LOT of extra weight... engine, gearbox, big heavy generator, and oodles of gallons of Jet-A.

If there is a fire, there is a HUGE problem. You don’t need range extenders, you need to get on the ground (or ditch the plane). All the cells need to be in “fire resistant” containers with a method to cool them, like water or foam. There also needs to be a method to expel the excess pressure from heat generated by fire, so each cell enclosure needs a water drain and pressure relief.
 
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Dan Thomas

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Propellers on the wing tips has got to be the dumbest idea, designed by people who don’t fly. They will likely attract lots of venture capital from equally dumb people.
We pointed that out on Pilots of America and got called the usual names like Luddites or cranky old guys. There are at least two serious problem with that wingtip prop setup: If one motor fails, you have to instantly shut the other one down too or totally lose control. The other is the problem of crosswind landings: if you have a few inches of clearance under that prop, how do you bank to slip for landing? And if you crab it on, it will either dig the downwind tip in or groundloop, probably both. The airplane started out as a trike and became a taildragger, probably because it ended up so tail-heavy that the nose wouldn't stay down. So now they'll have a lifting tail or something close to it and equally unstable and will need fancy computers to fly the thing.

And that tail prop. Right where the tailwheel will kick up FOD for it to chew on.

It looked to me like it was designed by some non-pilots and certainly non-aero engineers. Since they lost the prototype to the fire it might not go anywhere now.
 
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Tony Williams

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We pointed that out on Pilots of America and got called the usual names like Luddites or cranky old guys....

It looked to me like it was designed by some non-pilots and certainly non-aero engineers. Since they lost the prototype to the fire it might not go anywhere now.
All the metrics that they proposed were all pie-in-the-sky... range, payload, etc. Snake oil salesmen.

Hopefully, burning this one down might have saved a few lives.
 
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