13yo Invents a Better Hyperloop - It's still a STUPID IDEA

[Fungus]

Leo's machine did not fly.

Yeah, what a dumbass he was...

[SparkyFX]

The need for the vacuum is the tricky part of the concept, as you could have a very low drag of the vehicle as long as the air surrounding the train moves as fast as the train, which would be possible in a closed pipeline. Unfortunately you would need to invest the energy to push the whole mass of air inside the tube and accommodate it's friction on the inner diameter as well.

I don't know how much less friction a gas in a solid tube has by reducing it's pressure, as that's some advanced aerodynamics, not solvable by taking the cross sectional area into consideration alone and the length of the tube is undefined so far.
Conventional trains go too slow for this to be significant, high speed trains just use a modified frontal section and probably max out by limitations of the chassis. Their length is very limited compared to the inner diameter of a 1000km tube, therefore I guess air resistance itself is not the big factor to conventional trains. So it either needs 1000km/h and magnetic levitation/very advanced chassis to actually matter or it is a lot of effort for very little gain. At the same time the losses for a Hyperloop are hidden in the pneumatic propulsion system (sled as a piston). Which means the longer the tube, the more losses you get in (gas) friction.

Then the change in temperature by the expanding propulsion-gas (or even just residual gas moving, or condensed water inside condensing) would be a problem in itself to such a structure. That would need some high-tech materials in the assembly, with stable temperature coefficient, high-strength or at least accommodated for it. A slick (steel-) tube wont cut it.

There might be solutions to these problems, the tube would not need to be slick, it could be corrugated or be the bellow frame, the pressure reduction could be a feature within the grooves (like pistons that move outward to reduce the pressure by some amount), it is the unknown length and the additional requirement of reduced internal pressure that increases requirements dramatically. I mean I get into the fallacy of the concept drawing and start using these in my mind before thinking about what they are, just a concept drawing.

Anyway, things figured out or not, all these things (and all not-yet-discovered ones) add up and all speak against breaking even to make a business model that works competitively against conventional trains. If there are advantages, they come from shifting from/to another inefficiency or at the cost of safety.

It is new, it is a great mind-bender, maybe even a great advertisement to involved parties, but kind of hopeless, it represents the search for a new inspirational pie-in-the-sky project.

[Connecteur]

Leo' s machine did not fly and will not fly

So? You can bet he'd have figured out the need for a tail rotor after a single prototype, etc.

Also: Most of his drawings had deliberate flaws in them, eg. this one:
(Attachment Link)

Would that have moved anywhere if you built one? No.

Do you think he didn't know that...?

Pretty good imagination for someone with no aeronautical experience, no resources and no science.  The average person at the time was glad to have survived another day.

[EEVblog]

This one shows the airlock, it has to hold back around 120 tons.
https://interestingengineering.com/virgin-hyperloop-one-sets-new-speed-record-at-240mph

That's one heck of a door.
And you'll need two of these at each end.
The two inner ones hold the main low pressure for the entire length.
The two outer doors for a small airlock to allow the pod to enter. You then have the choice of pumping out the air in the airlock and then opening the inner door. Or you can just open the inner door and the high pressure in the airlock mixes with the pressure in the main tube length.

The Hyperloop is obviously useless for short trips and frequent stops.

[EEVblog]

The only real engineering problem of Hyperloop is "low pressure". If somebody solves that or comes up with a way to not need such low pressures then it's game-on.

No, it's not game-on, it's game-over. Because Hyperloop without the low pressure tube is just MagLev, and that already exists.

[EEVblog]

With Hyperloop what if the low pressure system fails, what's the propulsion backup system? or does the entire 100km or whatever system just shut down?
Do they send in the pusher cart?
Also, how do you do contraflow on the system? Existing trains (that are much simpler systems) break down all the time and require ways to route the traffic around issues.

[EEVblog]

So it's been two years since they achieved 387km/h. Have they beaten that after two years?
Nothing in press releases it seems? 

[Fungus]

With Hyperloop what if the low pressure system fails

I assume there'll be enough redundancy built into the system to avoid that.

[Connecteur]

So it's been two years since they achieved 387km/h. Have they beaten that after two years?
Nothing in press releases it seems? 

Potential design flaws don't disprove proof of concept.
Just to be clear, that doesn't prove it either.

I respect the opinions of people with sufficient engineering and scientific knowledge, but we know they don't always agree.

[StillTrying]

That's one heck of a door.

I think the door on that test track might be just a 'moving model', not capable of sealing the near vacuum travel part of the tube from the 1atm. station part.

[Altair8800]

Jokingly, you should never "assume"...    




We are engineers and scientists and the devil is in the details...  But the details are very, very important...

[EEVblog]

That's one heck of a door.

I think the door on that test track might be just a 'moving model', not capable of sealing the near vacuum travel part of the tube from the 1atm. station part.

Looks like an o-ring seal to me.
And how did they get the test speed without lower pressure?

[EEVblog]

So it's been two years since they achieved 387km/h. Have they beaten that after two years?
Nothing in press releases it seems? 

Potential design flaws don't disprove proof of concept.
Just to be clear, that doesn't prove it either.

I'm not talking about design flaws, I'm simply asking why they haven't gotten faster speed?
Are they limited by the length of the test track?
If they got 387km/h and the test was success, why not extend the test track and prove the full speed. That would help shut up all the critics, help get more funding, and help further prove the design concept.
They have the space in the desert, they have the money presumably, and it's been two years, so why haven't they gone faster? 

Also, how is that test pod levitated? Are those electromagnets on the bottom on the single rail? Doesn't like a traditional maglev, looks like it would be unstable?
Is it even levitated at all?, or is it just pushed on rollers or something?
Also at 1:38 you can see a break in the bottom rail.
Looks like they have some form of outside box on every 2nd pillar. Power for the Maglev? and/or vacuum pumps?

[StillTrying]

Looks like an o-ring seal to me.
And how did they get the test speed without lower pressure?

By lowering the pressure in the whole tube.

https://youtu.be/zcikLQZI5wQ?t=250   The 'station door' part ?

https://youtu.be/zcikLQZI5wQ?t=328   There's no visible 'station door' on that one.

[jonovid]

Looks like an o-ring seal to me.
And how did they get the test speed without lower pressure?

By lowering the pressure in the whole tube.

https://youtu.be/zcikLQZI5wQ?t=250   The 'station door' part ?

https://youtu.be/zcikLQZI5wQ?t=328   There's no visible 'station door' on that one.

after 5 yrs of research and development 
looks like the only thing that has improved here,  is the quality of the promotional videos.

[StillTrying]

the quality of the promotional videos.

This bit shows the station door opening ahead of the train, but the video cuts to a no-door version before the train moves off, perhaps it can't get across the gaps in the track.
https://youtu.be/zcikLQZI5wQ?t=358

[GeorgeOfTheJungle]

Or perhaps it's all fake...

"The whole problem with the world is that fools and fanatics are always so certain of themselves, but wiser people so full of doubts"

[StillTrying]

I didn't know that Thunderf00t had done one on the CNNtravel article.