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Airbus pioneers a superconducting powertrain cooled by liquid hydrogen

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Re: Airbus pioneers a superconducting powertrain cooled by liquid hydrogen

#21
post #14

Earlier quoted context omitted.

Yeah, people don't like being told they fell for exactly what the editor who chose the title wanted them to fall for.

No, ignorant editorial bloviating is specifically forbidden in the ToS.

The article is clearly greenwashed with respect to the potential impact of the tech (it's at such an early stage lord knows where if any applications in which it will be used). This is corporate press release SOP. Calling it out as wasted words to be ignored or disregarded isn't "editorial bloviating".

And they're guidelines, not a ToS.

Re: Airbus pioneers a superconducting powertrain cooled by liquid hydrogen

#22
Cool idea. I would be more enthused if it came from another company though. It seems like all the "green" projects Airbus does are aborted.

Remember their last electric plane? Canceled before the first flight. Meanwhile a couple startups are successfully retrofitting electric propulsion on light aircraft.

Re: Airbus pioneers a superconducting powertrain cooled by liquid hydrogen

#23
post #20
post #13

Earlier quoted context omitted.

This is the difference between electric and combustion powertrains, no? In electric, heat is the enemy and inefficient. In combustion, heat is a key component of the thermodynamic efficiency, unavoidable, and effectively only limited by material tolerances. (I didn't major in physics, so someone keep me honest on the ceiling / floor efficiency equations for combustion engines?)

You still have to cool a combustion engine - hence why car's have radiators. Combustion engine's are also limited by Carnot cycle engine efficiency - about 64% theoretically, no more then 50% in the real world. So you're still going to wind up having to dump progressively more heat from a fixed surface area.

(Post coffee) Cars have radiators to cool the operating structure (e.g. engine block), but that cooling's ancillary to power produced, no?

Carnot cycle was what I was grasping for.

Original point being that in a thermal engine, increasing your temperature gradient by increasing your high-temperature side (while holding exhaust constant) leads to more potential power.

Or IOW, a thermal engine that doesn't burn hot somewhere isn't going to produce much power.

(Electric being a completely different ball of wax)

Re: Airbus pioneers a superconducting powertrain cooled by liquid hydrogen

#24

This makes no sense to me. Don't you also need cryogenic systems to keep the H2 cold? Wouldn't those use waaaaay more energy than what you save with superconducting motors? Maybe they are talking about short haul flights where the H2 is ground cooled and then used as a cold sink but then in order to keep your electronics cold you're carrying lots more fuel than you need. TFA was too thin to pass the sniff test.

This is effectively regenerative cooling, like what rockets are commonly using. There are no cryogenic systems onboard, but all the fuel is loaded as very cold, and you can use the fuel as a coolant just before you burn it.

They will, however, be using kerosene, not liquid Hydrogen. It cannot provide cryogenic temperatures.

Re: Airbus pioneers a superconducting powertrain cooled by liquid hydrogen

#25

Earlier quoted context omitted.

This is effectively regenerative cooling, like what rockets are commonly using. There are no cryogenic systems onboard, but all the fuel is loaded as very cold, and you can use the fuel as a coolant just before you burn it.

They will, however, be using kerosene, not liquid Hydrogen. It cannot provide cryogenic temperatures.

Did you read the article? It was specifically about future liquid hydrogen-powered aircraft.

Re: Airbus pioneers a superconducting powertrain cooled by liquid hydrogen

#26
>"Liquid H2's key drawcard to aircraft designers is its impressive energy density by weight, but Airbus believes there are serious opportunities to be explored in another of its properties: temperature. To keep it liquid, it needs to be stored cryogenically at -253.15 °C (-423.7 °F), and Airbus figures that if you've got a monster cold source like that on board your aircraft, you might as well make use of it.

The theory is that the

liquid hydrogen can supercool the entire electric powertrain down to superconducting temperatures, at which point resistance virtually disappears from the system, and efficiency skyrockets.

A powertrain designed to take full advantage of this effect, reasons Airbus, could get the same job done at less than half the weight, half the electrical losses and reduced voltages.

So it's building one. The Ascend system will be a ground-based proof of concept developed over the next three years.

It'll be a 500-kW (670-hp) powertrain

, with cables, controllers, electronics and motors that are cryogenically cooled by liquid hydrogen pumped around in a circuit from the fuel tanks."

PDS: Seems like this could have electric antigravity ("electrogravitic") applications -- but as of this point in time, the theory of exactly how to do that seems lacking...

Still, the immense power (500-kW) and superconductivity aspect of things, seems to be there -- perhaps what's needed is for someone or some group to do some electric anti-gravity experimentation with this infrastructure...

Can they get weight loss electrically -- even as little as an ounce -- using all of that electricity and superconducting apparatus -- in some new, novel fashion?

?

Re: Airbus pioneers a superconducting powertrain cooled by liquid hydrogen

#27

The failure modes are going to be interesting, to say the least...

Yeah, It would be great if any fires were to burn clean and had a strong tendency to rise away from the aircraft, particularly for ground fires. H2 is also nice in that it doesn't create a lot of infrared energy while it burns. You might be able to save the weight of any fire suppression systems.

I think OP meant that electric motor losing superconductivity in-flight will cause irreversible run-away heating of the motor. Which must be mitigated by having more motors than nominally needed, all with independent power supply and cryogenic contours.

Re: Airbus pioneers a superconducting powertrain cooled by liquid hydrogen

#28

Earlier quoted context omitted.

Yeah, It would be great if any fires were to burn clean and had a strong tendency to rise away from the aircraft, particularly for ground fires. H2 is also nice in that it doesn't create a lot of infrared energy while it burns. You might be able to save the weight of any fire suppression systems.

I think OP meant that electric motor losing superconductivity in-flight will cause irreversible run-away heating of the motor. Which must be mitigated by having more motors than nominally needed, all with independent power supply and cryogenic contours.

The way I see it, losing superconductivity instantly shuts down the motor by tripping the circuit breaker, and causes it to transfer it's momentum energy into the surrounding liquid hydrogen. Some hydrogen might boil off, but it's nothing a safety valve can't handle.

The plane can then glide to the closest airport or switch to a non-superconducting mode.

Re: Airbus pioneers a superconducting powertrain cooled by liquid hydrogen

#29
post #7

This makes no sense to me. Don't you also need cryogenic systems to keep the H2 cold? Wouldn't those use waaaaay more energy than what you save with superconducting motors? Maybe they are talking about short haul flights where the H2 is ground cooled and then used as a cold sink but then in order to keep your electronics cold you're carrying lots more fuel than you need. TFA was too thin to pass the sniff test.

I think the idea is to use the H2 both as fuel and refrigerant.

So you recover the boiloff and use it to power a generator which powers a drivetrain cooled by the liquid hydrogen. This seems like a good idea.

Re: Airbus pioneers a superconducting powertrain cooled by liquid hydrogen

#30

>"Liquid H2's key drawcard to aircraft designers is its impressive energy density by weight, but Airbus believes there are serious opportunities to be explored in another of its properties: temperature. To keep it liquid, it needs to be stored cryogenically at -253.15 °C (-423.7 °F), and Airbus figures that if you've got a monster cold source like that on board your aircraft, you might as well make use of it. The the…

Electrogravitics is pure pseudo-science, anti-gravity bullshit, not supported in any way by our current understanding of physics or any experiment.

However, superconductivity (and using liquid hydrogen both as energy source and coolant) may be useful for ion thrusters; see:

-https://www.researchgate.net/publication/245438424_Supercond...

-https://www.nasa.gov/directorates/spacetech/strg/vitucci.htm....

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