Electric Planes

[lobosrul5]

Signal spreads over millions of miles, and we don't much care if we're a little off-target.

Throwing heavier-than-air-flight amounts of energy out of the sky, towards a moving plane with the inhabited surface of the Earth in the background seems like a terrible place for "aiming should not be too big a problem".

Overland routes could be served by ground stations. If they miss the beam will just dissipate. Oversea routes could be served by satellites beaming energy down. If they miss, you might kill some whales or something I suppose. Or a very unlucky ship is hit. This is pie in the sky, maybe 22nd century tech IMO.

 

[catsmate]

This?

LTA zeolite membranes: current progress and challenges in pervaporation

No, Lighter Than Air solids.

 

[Ziggurat]

Well, it sounds crazy enough to be a possibility. Aiming should not be too big a problem. We can aim a signal at a space-probe millions of miles away.

Hans

Aiming is an incredible problem. And the reason isn't because of what happens if you don't hit the plane's receiver. It's if you hit the wrong thing instead. That's a problem you really don't have with space probes. You're beaming microwaves with enough power to fly a plane, then it's also enough power to kill a person, or potentially degrade the structural integrity of a plane. A focused microwave beam like that is basically a weapon. And having a bunch of them all over the place is VERY risky.

 

[ynot]

Wonder if this “Range Extender” concept might make EV flight more a viable candidate?

https://www.youtube.com/watch?v=xthZVgbUnVU

Small, lightweight ICE motor generates electricity to increase overall amount of electricity available.

Hybrid plane I guess, but ICE motor doesn't directly drive props, just generates electricity to batteries.

 

[MRC_Hans]

Signal spreads over millions of miles, and we don't much care if we're a little off-target.

Throwing heavier-than-air-flight amounts of energy out of the sky, towards a moving plane with the inhabited surface of the Earth in the background seems like a terrible place for "aiming should not be too big a problem".

The last part is for satellites. Sapellites with that sort of power to spare are still science fiction. Aiming a beam from the ground at an airplane is current technology, but you touch at a central problem: Even with the best optimations, we are talking about hundreds of kilowatts. To transfer that without risk of collateral damage is not simple.

Hans

 

[Gord_in_Toronto]

No, Lighter Than Air solids.

Ah.

 

[MRC_Hans]

Aiming is an incredible problem. And the reason isn't because of what happens if you don't hit the plane's receiver. It's if you hit the wrong thing instead. That's a problem you really don't have with space probes. You're beaming microwaves with enough power to fly a plane, then it's also enough power to kill a person, or potentially degrade the structural integrity of a plane. A focused microwave beam like that is basically a weapon. And having a bunch of them all over the place is VERY risky.

I did not intend to allege that aiming at a distant space probe is the same thing, just that it is the same basic technology. To actually communicate with a trans Saturn probe, two-way, you can't just spread power over a large area and hope to pick it up. You might do that from Earth, but the probe does not have that sort of energy available. The signal strength loss would be prohibitive.

The considerable energy levels needed to remotely recharge an e-plane are, as you are noting, the main challenge. One would probably need to use a transmitter array, so you can focus the beam in three dimensions.

As I stated initially: The idea is crazy enough to have a chance. This was, of course, an ironic comment, but we have seen other crazy ideas come true.

Hans

 

[Gord_in_Toronto]

Then there is this:

Lilium Jet - Electric Ducted Jet Engine Aircraft



Latest progress here:
Test Flight September 28: Lilium Jet Demonstrates Maneuverability

Extremely interesting technology!

 

[ynot]

Then there is this:

Lilium Jet - Electric Ducted Jet Engine Aircraft



Latest progress here:
Test Flight September 28: Lilium Jet Demonstrates Maneuverability

Extremely interesting technology!

A detailed analysis by an independent expert.

 

[Gord_in_Toronto]

A detailed analysis by an independent expert.

I followed most of that and it appears that engineering and physics trump hype and very good computer generated videos. There is no way you can combine VTOL and long range flight. Pity.

Lilium selects the use of a huge number of design approaches to create an "optimal" aircraft design and I am left wondering if any of the technologies will actually work, in whole or in part, and supply efficiencies; albeit at lower levels.

Theranos anyone?

 

[Roger Ramjets]

I followed most of that and it appears that engineering and physics trump hype and very good computer generated videos. There is no way you can combine VTOL and long range flight. Pity.

Of course you can - just not the way they are doing it.

Lilium selects the use of a huge number of design approaches to create an "optimal" aircraft design and I am left wondering if any of the technologies will actually work, in whole or in part, and supply efficiencies; albeit at lower levels.

Theranos anyone?

Nope, nothing like Theranos. No secret tech that you just have to trust them on - and the demonstrator model actually flies! Whether it will ever be commercially viable is another matter of course, but the technology definitely works - unlike Theranos.

I skipped through the 'detailed analysis by an independent expert' video because I don't have the time or patience to watch the whole 1 hour 40 minutes. The gist of it seems to be skepticism that the Lilium Jet can achieve its claimed range, not 'will it work?'. We know it works, so the title is clickbait.

 

[zooterkin]

Zeroavia are developing electric motors, powered by hydrogen cells, to replace the engines on existing planes. https://zeroavia.com/flight-testing/

We have retrofit our prototype ZA600 engine to power the left side propeller of our Dornier 228. The aircraft made history with a milestone first flight on January 19th 2023. The subsequent flights are all part of our bid to build understanding ahead of submitting for certification by the close of this year. ZeroAvia intends to power zero-emission commercial aircraft by 2025.

 

[smartcooky]

I followed most of that and it appears that engineering and physics trump hype and very good computer generated videos. There is no way you can combine VTOL and long range flight. Pity.

Well, you can in conventionally powered aircraft. The V-22 Osprey, a VTOL tiltrotor has a ferry range of almost 4,000 km, and an operational range over 2000 km.

However, it gets difficult with electrically powered aircraft, although recent developments with "solid state" batteries could see some advances.

https://www.topspeed.com/everything...ame-changing-solid-state-battery-breakthrough

"Keiji Kaita, the president of Toyota's research and development center for carbon neutrality, told Financial Times that Toyota is now capable of producing a solid-state battery that can deliver a mind-blowing range of 745 miles (1200 km), and astonishingly, it can be fully charged in 10 minutes or even less. And Set aside the impressive range for a second, and consider the freakishly fast charging time, which is only slightly longer than it takes to grab a takeaway coffee. This is five minutes faster than the current quickest-charging 2023 Lucid Air. Looking to the future, Toyota has set its sights on integrating these advanced solid-state batteries into its EV lineup by 2027."​

Solid state batteries have between 2 and 2½ times the energy density of Lithium Ion batteries

https://www.flashbattery.tech/en/how-solid-state-batteries-work/

This allows them to be lighter for the same power, or the same weight for a greater power. They also have a significantly shorter charge time, and because they have a solid rather than a liquid electrolyte, they do not have the propensity to explode or catch fire. In terms of electric aircraft this translates directly to increased range, less down time and better safety.
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[Lplus]

Well, you can in conventionally powered aircraft. The V-22 Osprey, a VTOL tiltrotor has a ferry range of almost 4,000 km, and an operational range over 2000 km.

However, it gets difficult with electrically powered aircraft, although recent developments with "solid state" batteries could see some advances.

https://www.topspeed.com/everything...ame-changing-solid-state-battery-breakthrough

"Keiji Kaita, the president of Toyota's research and development center for carbon neutrality, told Financial Times that Toyota is now capable of producing a solid-state battery that can deliver a mind-blowing range of 745 miles (1200 km), and astonishingly, it can be fully charged in 10 minutes or even less. And Set aside the impressive range for a second, and consider the freakishly fast charging time, which is only slightly longer than it takes to grab a takeaway coffee. This is five minutes faster than the current quickest-charging 2023 Lucid Air. Looking to the future, Toyota has set its sights on integrating these advanced solid-state batteries into its EV lineup by 2027."​

Solid state batteries have between 2 and 2½ times the energy density of Lithium Ion batteries

https://www.flashbattery.tech/en/how-solid-state-batteries-work/

This allows them to be lighter for the same power, or the same weight for a greater power. They also have a significantly shorter charge time, and because they have a solid rather than a liquid electrolyte, they do not have the propensity to explode or catch fire. In terms of electric aircraft this translates directly to increased range, less down time and better safety.
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The charge current must be massive.

 

[jeremyp]

And this is not the first retrofit.

Back in 2019, Harbor Air (Vancouver BC) began retrofitting a DHC2 Beaver Seaplane with a 750 HP Magnix electric motor. It made its first test flight in the same year. But as is usual with any new technology, the innovators are outpacing the bureaucrats and paper pushers' ability to keep up. The FAA have been dragging their feet and have taken four years so far just to certify the engine to power a passenger aircraft.

Nonetheless, there are a couple of very interesting aeronautical engineering aspects to converting this type of aircraft.

1. The standard DHC-2 does not carry fuel in its wings. All the fuel is stored in belly tanks. During the retrofit, the belly tank is replaced with batteries that are shaped and designed to fit in the fuel tank space. Its need to carry more batteries than the tank space will hold, so some additional batteries have to be distributed under the floor in such a way as to maintain weight and balance (C of G). Of course, as battery efficiencies improve, fewer and fewer batteries will have to be carried
2. The standard DHC-2 is fitted with a an R985 Wasp Junior radial engine and its power curve is very specific - it has a limited range of RPM over which the most power is developed. Therefore, propellers have to be designed in such a way as to take advantage of the peak in the power curve. They must have finer pitch at low RPM to allow the engine to quickly spool up to the RPM where the power is, so the propeller pitch can be increased to give maximum propulsion. But electric motors work differently. They provide almost instant power from low RPM evenly across the whole range. And that power is available immediately the throttle is pushed up. This means propellers can be designed to operate with coarser pitch at low RPM too.

Never going to happen. The energy density of a battery is a physical property of the material it is made of. Lithium is already about the least dense material you can make a battery out of. You may get some small gains by improving the packaging and the efficiency of the motors, but you'll never get to the point where you can just take the fuel tanks out of a plane and replace them with batteries and have anything like the same performance.

 

[jeremyp]

Yeah, I agree. This plane could fit nicely into a niche of short, over water, low demand, flights. Although they will need recharging infrastructure put in at those airports. But, the savings of having to ship in fuel to islands, or other remote airports, will make it worth it over the long run I imagine.

And what happens if you fly from Nelson to Wellington with your 200km range and Wellington is fogged in? Or it's busy and they want to put you in a holding pattern for a while?

 

[Planigale]

And what happens if you fly from Nelson to Wellington with your 200km range and Wellington is fogged in? Or it's busy and they want to put you in a holding pattern for a while?

Shouldn't be a problem in Orkney. Can't imagine that you would ever be in a holding pattern, and given the flight from Westray to Papa Westray is 90s even an electric plane can return / idle.

Notoriously one pilot made the flight backwards, in a high wind he maintained flight speed above stalling speed, but below wind speed and allowed his plane to be blown backwards from Westray to Papa Westray, it is a common sight in Orkney to see birds flying backwards.

 

[Gord_in_Toronto]

Of course you can - just not the way they are doing it.

Nope, nothing like Theranos. No secret tech that you just have to trust them on - and the demonstrator model actually flies! Whether it will ever be commercially viable is another matter of course, but the technology definitely works - unlike Theranos.

I skipped through the 'detailed analysis by an independent expert' video because I don't have the time or patience to watch the whole 1 hour 40 minutes. The gist of it seems to be skepticism that the Lilium Jet can achieve its claimed range, not 'will it work?'. We know it works, so the title is clickbait.

Sorry, I went a bit overboard after spending all that time listening to the video. The claim does seem to be "it won't work as advertised". So there is hype involved. I'm fully aware the VTOL aircraft work, in particular as my dad worked as an engineer at Canadair when it developed the CL-84 Dynavert in the early 1960s. It truly was an aircraft before its time.

 

[smartcooky]

Never going to happen.

Already has...

https://www.flashbattery.tech/en/how-solid-state-batteries-work/

The greater intrinsic safety helps bring another major improvement: the use of a pure metal anode encourages a huge increase in energy density. This is essentially down to the removal of the graphite anode (which in lithium-ion batteries contains the ions when they migrate).​

​

How does a solid-state battery work?
When the cell is charging, the lithium particles move from the cathode, through the structure of the atoms that form the separator, and then move in between the separator itself and the anode’s electrical contact, thus forming a solid layer of pure lithium. In this way, the anode will only be formed of lithium particles and will have a smaller volume than a lithium-ion technology anode.​

The energy density of a battery is a physical property of the material it is made of. Lithium is already about the least dense material you can make a battery out of.

Lithium density is not the only factor governing weight.

In a solid-state battery, during the transfer, only the ions remain and a bulky, heavy compound part is removed which does not actively help generate energy.​

According to the latest studies, solid-state batteries have an energy density 2-2.5 times higher than current lithium-ion technology and this huge advantage would result in a lighter and smaller battery..​

You may get some small gains by improving the packaging and the efficiency of the motors, but you'll never get to the point where you can just take the fuel tanks out of a plane and replace them with batteries and have anything like the same performance.

A strawman - no-one here claimed this!

* * * * * *

And solid state batteries are about to go into production.

https://pressat.co.uk/releases/quan...electrolyte-da6ab5c47ea238854e2c06a76717612d/

German start-up develops the world’s first solid-state battery ready for series production – Outstanding properties: no cobalt, 10 times longer service life and non-flammable electrolyte
The Bonn-based company High Performance Battery (HPB) has achieved a decisive breakthrough in battery and storage technology: a team led by Prof. Dr. Günther Hambitzer has developed the world’s first solid-state battery with outstanding properties to production readiness. The applications range from stationary storage for home and industrial use to charging infrastructures and the mobility segment – such as the automotive industry. “We are not only opening a new chapter in battery technology,” explains Sebastian Heinz, CEO of HPB, “but are also making a decisive contribution to the energy transition and climate protection worldwide”.

The data and properties measured so far show significantly better values and characteristics compared to the currently dominant lithium-ion batteries.​

 

[smartcooky]

And what happens if you fly from Nelson to Wellington with your 200km range and Wellington is fogged in? Or it's busy and they want to put you in a holding pattern for a while?

Having been on that flight literally several dozens of times in the last 50 years, I can tell you exactly what happens... you see, in this country, we have a couple of things you may not have heard of. They are called "Weather Reports" and "Radio Communications"

If Wellington is socked-in, the flight does not take off to begin with. If on some one in a million occasion the fog suddenly and unexpectedly closes in during the 45 minutes after the flight has already taken off, it either turns back or diverts to Blenheim (an airport it overflies on the way to Wellington.