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tantricengineer t1_jarnif0 wrote

Reply to comment by MightyH20 in Universal Hydrogen Successfully Completes First Flight of Hydrogen Regional Airliner by tooch_my_gooch

These systems must store hydrogen at thousands of PSI for the energy density to rival petrol based fuels. The ideal storage state is nearer to 10,000 PSI where hydrogen becomes slurpy-like in composition.

The material science is coming along. One challenge with hydrogen fuel tanks is if a tank is punctured in an accident, you have rapid expansion of hydrogen gas as it equalizes to atmospheric pressure, and a likely fire which has little color. (Look at the FLIR view here: https://youtu.be/0aDC2ZmikRE )

This makes it difficult to determine where flames are.

Still rooting for this tech though since it gives us amazing possibilities.

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kyckling666 t1_jarrzfd wrote

Guys I grew up with in oil and gas used straw brooms for invisible fire detection.

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jawshoeaw t1_jasas4x wrote

in an aircraft I'm guessing explosive decompression is the bigger problem, seeing as visualizing a fire on your wing really isn't changing your plan in the short term lol

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tantricengineer t1_jat4mfi wrote

I don't expect these tanks to blow up in flight. I expect them to blow up when most commercial aircraft accidents happen: on the ground / takeoff / landing.

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jawshoeaw t1_jat9lnt wrote

Ohhh gotcha. But sadly that’s rarely survivable with current fuels. I could see some edge case where there’s a survivable landing but here’s the actual advantage of hydrogen, the high pressure vessels are necessarily quite strong and might do better in a crash even if the broke open compared to avgas

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InsuranceToTheRescue t1_jasszm4 wrote

I believe since the tanks are pressurized that they would likely explosively ignite instead of making a sustained flame. Then these vehicles really could blow up like in the movies.

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