All of the Hyperloop development efforts are ignoring the elephant in the room: thermal expansion. If you do the math, the ends of a viable hyperloop track will have to move hundreds of meters [1]. No one has yet advanced even a viable idea for how to deal with that, let alone an actual design. Until that happens, the Hyperloop is vaporware. [1] It's a trivial calculation. The thermal expansion coefficient of steel i…
Yeah, Elon Musk never thought about that because he was busy landing rockets. Come on.. why do you think he did not think about that? By the way, curves in the track can eliminate this when they can slide a little. And I can imagine there are more and better solutions.
Hyperloop One Becomes ‘Virgin Hyperloop One’
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Re: Hyperloop One Becomes ‘Virgin Hyperloop One’
#42All of the Hyperloop development efforts are ignoring the elephant in the room: thermal expansion. If you do the math, the ends of a viable hyperloop track will have to move hundreds of meters [1]. No one has yet advanced even a viable idea for how to deal with that, let alone an actual design. Until that happens, the Hyperloop is vaporware. [1] It's a trivial calculation. The thermal expansion coefficient of steel i…
We could replace steel with a low coefficient metal matrix composite without sacrificing stiffness or long range strength. It would blow out the cost structure however ;)
Have also heard anecdotally that condensation in the tube could be a real problem. Even at near vacuum, the rapid pressure differentials can cause buildups in front of and behind the speeding vessel.
Re: Hyperloop One Becomes ‘Virgin Hyperloop One’
#43When are we going to address the elephants in the room? Just the tube alone: - largest pressure vessel in the world. How do you keep it at near vacuum? - Thermal expansion over such a large distance, especially if the top of the tube is warmer than the bottom. - Safety, how does an evacuation look like if the tubes are sealed?. There are many more. Some how I feel like this is a "pipe" dream. Lots of marketing, very…
I haven't done any work on hyperloops. But expansion seems to be a problem already solved by industry a long time ago: https://en.wikipedia.org/wiki/Metal_expansion_joint
Metal expansion joints can't hold a vacuum.
Re: Hyperloop One Becomes ‘Virgin Hyperloop One’
#44I see so many negative comments about this, but in my opinion everything has to start somewhere. It doesn't matter how crazy and impossible it looks, it will be done eventually (and we have plenty of examples). Maybe we will not teleport in 2 seconds across the globe or this project will die, who knows if we don't try. A little bit of optimism doesn't hurt. Just saying. And for Virgin, it's not my money, if they want…
So much this. Especially when people chime in with some minor detail means it will fail because clearly 'must not have thought of it' if they didnt mention in some 400 word press release.
Its like Elon going into trucking and people saying the range isn't sufficient. The guy is pretty darn smart. I'm confident he understands trucking range and has some solutions, and simply isn't discussing it for secrecy and/or succinctness.
Re: Hyperloop One Becomes ‘Virgin Hyperloop One’
#45All of the Hyperloop development efforts are ignoring the elephant in the room: thermal expansion. If you do the math, the ends of a viable hyperloop track will have to move hundreds of meters [1]. No one has yet advanced even a viable idea for how to deal with that, let alone an actual design. Until that happens, the Hyperloop is vaporware. [1] It's a trivial calculation. The thermal expansion coefficient of steel i…
This point is clearly addressed in the paper: The ends of the tube can slide 300 meters next to the station, and the tube is not firmly attached to the pylons but can move to accommodate the expansion.
Re: Hyperloop One Becomes ‘Virgin Hyperloop One’
#46When are we going to address the elephants in the room? Just the tube alone: - largest pressure vessel in the world. How do you keep it at near vacuum? - Thermal expansion over such a large distance, especially if the top of the tube is warmer than the bottom. - Safety, how does an evacuation look like if the tubes are sealed?. There are many more. Some how I feel like this is a "pipe" dream. Lots of marketing, very…
I haven't done any work on hyperloops. But expansion seems to be a problem already solved by industry a long time ago: https://en.wikipedia.org/wiki/Metal_expansion_joint
Sounds promising:
- Resistance to high and very high pressures
- Large movement absorption
- Early leak indication (in case of damage) via standard check hole
- Complete burst resistance
- Possibility of permanent leak monitoring in critical media
Re: Hyperloop One Becomes ‘Virgin Hyperloop One’
#47Earlier quoted context omitted.
I haven't done any work on hyperloops. But expansion seems to be a problem already solved by industry a long time ago: https://en.wikipedia.org/wiki/Metal_expansion_joint
Metal expansion joints can't hold a vacuum.
Quick googling says otherwise: http://www.spiroflex.hr/expansion-joints-vacuum-technology
Re: Hyperloop One Becomes ‘Virgin Hyperloop One’
#48All of the Hyperloop development efforts are ignoring the elephant in the room: thermal expansion. If you do the math, the ends of a viable hyperloop track will have to move hundreds of meters [1]. No one has yet advanced even a viable idea for how to deal with that, let alone an actual design. Until that happens, the Hyperloop is vaporware. [1] It's a trivial calculation. The thermal expansion coefficient of steel i…
I dont know if this an elephant in the room. I'm guessing engineers have thought about this and just not discussed it publicly. They have some pretty smart guys.
Also to nitpick, from "the ends of a viable hyperloop track will have to move hundreds of meters" - this doesn't have to be true. There can be absorption points along the track. Overlaps. Or maybe they tunnel the entire way where its cooler. Or wrap the tunnel in something cooling and reflective. We dont have train tracks moving hundreds of meters do we? I dont profess to know the solution, but do know there are solutions somewhere.
Re: Hyperloop One Becomes ‘Virgin Hyperloop One’
#49I see so many negative comments about this, but in my opinion everything has to start somewhere. It doesn't matter how crazy and impossible it looks, it will be done eventually (and we have plenty of examples). Maybe we will not teleport in 2 seconds across the globe or this project will die, who knows if we don't try. A little bit of optimism doesn't hurt. Just saying. And for Virgin, it's not my money, if they want…
I'm not saying it can't work and we shouldn't try our best. However from what I have seen so far I am quite disappointed as even known issues aren't addressed at all. As if the people involved are blindly going at it instead of working with people who know something about pressure vessels etc. Sure sometimes you need an outside perspective but not like this.
Care to elaborate?
Re: Hyperloop One Becomes ‘Virgin Hyperloop One’
#50When are we going to address the elephants in the room? Just the tube alone: - largest pressure vessel in the world. How do you keep it at near vacuum? - Thermal expansion over such a large distance, especially if the top of the tube is warmer than the bottom. - Safety, how does an evacuation look like if the tubes are sealed?. There are many more. Some how I feel like this is a "pipe" dream. Lots of marketing, very…
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