this post was submitted on 09 Sep 2023
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World’s first crewed liquid hydrogen plane takes off::undefined

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[–] infeeeee@lemm.ee 15 points 2 years ago* (last edited 2 years ago)

That's not a new plane, that's the double fuselage version of Pipistrel Taurus: https://en.wikipedia.org/wiki/Pipistrel_Taurus

Pipistrel Taurus is a glider, first flown in 2004. There is an added benefit of using a glider for testing a new engine: gliders have a much better L/D ratio, so less power needed for longer flights, and if there is a malfunction they can land safely while gliding.

[–] A_A@lemmy.world 5 points 2 years ago* (last edited 2 years ago) (1 children)

LEL for Hydrogen: 4.0 (% in air)
UEL is 75 %
This is the most severe (wide range) for any fuel.
LEL and UEL Explained (Explosive Gas) - Projectmaterials

This is on top to hydrogen enbrittlement and low temperature enbrittlement of metals.

Good luck with the insurance fees for commercial flights.

[–] agressivelyPassive@feddit.de 4 points 2 years ago (2 children)

Aviation is the one field, where burning some form of carbohydrate is actually the only viable option. Batteries may be an option for short flights, but I don't see any solution for long haul flights.

Whether the fuel ends up being (synthetic) kerosene or some plant oil stuff doesn't really matter, the turbine isn't going anywhere.

Yeah getting aircraft onto renewable energy is probably the lowest priority, if everything else was renewable it wouldn't even matter if they were never renewable.

[–] A_A@lemmy.world 2 points 2 years ago

I agree...
( except for a small typo : it's carbohydride or hydrocarbon )

[–] j4yt33@feddit.de -5 points 2 years ago (2 children)
[–] Graphine@lemmy.world 6 points 2 years ago (1 children)

I like how you just assume that we haven't advanced technology or safety features at all since the 1930s.

[–] j4yt33@feddit.de 1 points 2 years ago

It was a joke

[–] A_A@lemmy.world -2 points 2 years ago (1 children)


The space shuttle contain a huge reservoir of liquid hydrogen at very low temperature creating extremely difficult engineering stresses.
So, insurance cost will be sky high if ever such planes take commercial flights.

[–] photonic_sorcerer@lemmy.dbzer0.com 8 points 2 years ago (1 children)

Well you know what else is explosive? Jet fuel!

[–] A_A@lemmy.world 5 points 2 years ago* (last edited 2 years ago) (1 children)

Do you know how brittle metals become at very low temperature ? Did you notice I did not talk about hydrogen explosiveness ?

But sure, let's now talk about explosiveness. Do you know the mixture ratio range is completely different (much greater) for air + H~2~ explosive mixture as compared to other mixtures ? You are very far from an expert on the topic aren't you ?

[–] Cleverdawny@lemm.ee 0 points 2 years ago (1 children)

Hydrogen isn't explosive, it's flammable. Just like jet fuel.

[–] A_A@lemmy.world 2 points 2 years ago (1 children)

Detonation
"A very wide variety of fuels may occur as gases (e.g. hydrogen), droplet fogs, or dust suspensions. In addition to dioxygen, oxidants can include halogen compounds, ozone, hydrogen peroxide, and oxides of nitrogen. Gaseous detonations are often associated with a mixture of fuel and oxidant in a composition somewhat below conventional flammability ratios."

For Hydrogen, if I recall correctly, the explosive range is from 4% to 75% hydrogen in air. I may dig a little bit more to find sources.

How many more false experts want to comment on this ? And feel free to downvote, you only underline your ignorance and arrogance.

[–] Cleverdawny@lemm.ee 1 points 2 years ago (1 children)

Yes, when you combine a flammable substance and an oxidant, you can get an explosive. But hydrogen is flammable. It isn't an explosive. Explosives have their own oxidants.