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Electric planes
- Thread starter doug
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- Electric Vehicles
Here is a cool piece, and neat video:
Ion drive meets drone, as small plane flies with no moving parts
A solid state aircraft - no moving parts, using ionic thrust
Ion drive meets drone, as small plane flies with no moving parts
A solid state aircraft - no moving parts, using ionic thrust
This article is 6 months old but a TMC search didn’t show any posts about it.
This 32kW plane will fly twice as high as commercial jets on SunPower
A super lightweight 2-person solar-powered plane designed to go to 60,000 ft. Cabin is not pressurized, so pressure suits would be required.
I love it. Solar power can keep it aloft for 12 hours.
Here is the project website, English version SolarStratos – To the edge of space
This 32kW plane will fly twice as high as commercial jets on SunPower
A super lightweight 2-person solar-powered plane designed to go to 60,000 ft. Cabin is not pressurized, so pressure suits would be required.
I love it. Solar power can keep it aloft for 12 hours.
Here is the project website, English version SolarStratos – To the edge of space
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Brando
Active Member
Brando
Active Member
Designed to take 9 passengers up to 650 miles at a cruise speed of 240 knots.
Alice will redefine regional transportation as an all-electric aircraft.
Alice Commuter | Eviation
Alice will redefine regional transportation as an all-electric aircraft.
Alice Commuter | Eviation
JRP3
Hyperactive Member
I wonder about the wing tip motors. Why not mount them closer to the body? Less stress on the wings thus a lighter wing structure, and I'd think easier to fly if one motor goes out.
Etna
Member
I've looked into it closely and even met the CEO. I was seated next to him at a conference by coincidence last year. Super nice guy but blissfully ignorant about the technical issues I raised to him about his aircraft. The scaled model that they flew gives them a false sense of confidence about their concept, as is typical for many startups.
The performance claims are based on an aluminum-air battery that is non rechargeable and costs about 4 times as much per mile than jet fuel. Both the aircraft concept and the battery are non-starters.
Pretty amazing how much traction they got in the media for the past couple of years.
@JRP3 the wingtip motors are extremely efficient when rotating opposite the wingtip vortices. But you cannot use these as primary propulsion because of engine out lateral control, as you point out. They only make sense in conjunction with one or more propellers closer inboard on the wing, like the Nasa X-57 Maxwell for example.
The performance claims are based on an aluminum-air battery that is non rechargeable and costs about 4 times as much per mile than jet fuel. Both the aircraft concept and the battery are non-starters.
Pretty amazing how much traction they got in the media for the past couple of years.
@JRP3 the wingtip motors are extremely efficient when rotating opposite the wingtip vortices. But you cannot use these as primary propulsion because of engine out lateral control, as you point out. They only make sense in conjunction with one or more propellers closer inboard on the wing, like the Nasa X-57 Maxwell for example.
The propeller design and positioning is interesting. Looks like this is a design on paper.
It is vaporware until you see pictures and videos of the prototype in action
swaltner
Active Member
Looks like an interesting design. Hope they can make it work, but with the issues already pointed out, that may not happen.
Some back of the napkin calculations to see if their stated specs sounds reasonable:
Ignoring the extra power demands to climb to a 10,000' cruise altitude and the lower power demands in a descent (let's call those differences a wash), they would need to keep the average power power demands to below 277 kW. That's coming from 900 kWh / 3.25 hours. 277 kW is 371 hp. Is that what one would expect for power needs on a 14,000 pound (6,350 kg) aircraft cruising at 260 knots? I'm only familiar with much lighter (2-4 seat) aircraft power demands. Compared to those power needs, this seems really low to me. The higher aspect ratio wings of the Alice Commuter should lower the power demands compared to a more traditional 10 person (9 passengers) aircraft, but would it be enough?
For comparison, NASA's X-57 Maxwell is projected to fly at 150 knots using 96.2 kW of power when in cruise flight. The Alice Commuter is expected to fly 73% faster than the X-57 and use 188% more power.
Some back of the napkin calculations to see if their stated specs sounds reasonable:
- 260 knots
- 650 mile range (with IFR reserve)
- 900 kWh battery
Ignoring the extra power demands to climb to a 10,000' cruise altitude and the lower power demands in a descent (let's call those differences a wash), they would need to keep the average power power demands to below 277 kW. That's coming from 900 kWh / 3.25 hours. 277 kW is 371 hp. Is that what one would expect for power needs on a 14,000 pound (6,350 kg) aircraft cruising at 260 knots? I'm only familiar with much lighter (2-4 seat) aircraft power demands. Compared to those power needs, this seems really low to me. The higher aspect ratio wings of the Alice Commuter should lower the power demands compared to a more traditional 10 person (9 passengers) aircraft, but would it be enough?
For comparison, NASA's X-57 Maxwell is projected to fly at 150 knots using 96.2 kW of power when in cruise flight. The Alice Commuter is expected to fly 73% faster than the X-57 and use 188% more power.
Etna
Member
I do these calculations for a living. The 650 mile range for a 14000 lb aircraft similar to a King Air requires at least 3200 kWh without reserves, at the shaft.
Obviously the 900 kWh battery claim shows that someone got his math wrong.
Obviously the 900 kWh battery claim shows that someone got his math wrong.
Brando
Active Member
Tesla took 5 years - 2017 +5 = 2022: less of chance than Tesla? probably - 2 years in -
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JRP3
Hyperactive Member
Tesla wasn't trying to do anything beyond the realm of technology and physics.
He says they will fly one in next year (2019) Paris air show. I doubt it. Shouldn't they be flying prototypes by now?
930 kWh looks awfully inadequate. But I hope they have done the math and engineering.
lolachampcar
Well-Known Member
Etna,
I'm too lazy to do the math so I'll just ask
Were your energy needs for the KA based on the efficiency of burning JetA in a PT6?
I'm too lazy to do the math so I'll just ask
Were your energy needs for the KA based on the efficiency of burning JetA in a PT6?
Etna
Member
@lolachampcar the energy need is calculated by flying the mission with a 3DOF performance model of the King Air with the actual PT6 engine deck. During the stepwise integration (steps of every second to 1 minute depending on the segments) I am integrating the shaft horsepower by the time increment to get the energy requirement of each step.
Thus I am not using Jet A fuel efficiency, although I get that as a byproduct.
Thus I am not using Jet A fuel efficiency, although I get that as a byproduct.
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lolachampcar
Well-Known Member
The Ultracapacitors, Electrodes, & Battery Manufacturing Tech Tesla Gets With Maxwell Technologies | CleanTechnica mentions that Maxwell (which Tesla very recently acquired) has demonstrated 300 Wh/kg batteries and claims to have identified a path to 500 Wh/kg batteries.
Are 500 Wh/kg batteries good enough for long range airplanes to stop burning liquid fuels?
Are 500 Wh/kg batteries good enough for long range airplanes to stop burning liquid fuels?
JRP3
Hyperactive Member
They probably are but that's not what Maxwell actually has. They are talking about cell level energy density, pack level will be much lower.
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