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| The Hyperloop: BUSTED |
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| Maxlor:
The wavefront might be bullet shaped actually, I haven't checked. If it is, it would be hard to see, since the plot is stretched 100x vertically as mentioned above. As for equations and so on: heh, I have no idea. I just put the geometry, fluid (air in this case) and pressure parameters into COMSOL's turbulent flow models, and tweaked the params a bit until it would finish the simulation in about 18 hours instead of 10 years, and then let it do its thing. And as for how COMSOL comes up with its results... eh that'd be quite an essay, but I'm sure someone has written it already :) |
| TheAmmoniacal:
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| Kilrah:
--- Quote from: Maxlor on July 26, 2016, 07:24:48 pm ---Second, why would the whole system have to be one open, connected tube? You could add a pressure lock every 1km that opens for cars and closes behind them, which would thus contain a catastrophe. --- End quote --- Now one fails to open: >1000km/h into a wall sounds awesome! |
| Maxlor:
--- Quote from: Kilrah on July 28, 2016, 06:14:49 pm --- --- Quote from: Maxlor on July 26, 2016, 07:24:48 pm ---Second, why would the whole system have to be one open, connected tube? You could add a pressure lock every 1km that opens for cars and closes behind them, which would thus contain a catastrophe. --- End quote --- Now one fails to open: >1000km/h into a wall sounds awesome! --- End quote --- Hehe yeah, that would be quite spectacular. So those locks better actually work :) And if they don't... well if you open them far enough in advance, the car can brake and stop before hitting it. Opening them about 6km ahead of a car should just about be enough. |
| Maxlor:
--- Quote from: EEVblog on July 28, 2016, 01:43:34 am ---He's doing back of the envelop calcs to show how impractical and fragile the system is going to be. You only need one of those showstoppers to be true to the entire project to be a guaranteed bust. --- End quote --- Nope, he's not. He's facepalming in a very elaborate way. If he has done back of the envelope calculations, he's certainly not showing them in the video. And yeah, I agree, one showstopper would be enough. But Thunderf00t hasn't demonstrated one. Personally, I think the likely showstopper is cost; if I were to try busting the hyperloop idea, I'd start there. Then again, this might become a prestige project that some government would be willing to throw unreasonable amounts of money at. It happens :-// --- Quote ---That implies that you think he's wrong and you have "obvious" solution to his argument. Please present those obvious and less obvious solutions. --- End quote --- No, I think he's making a fallacious argument: he's saying that some problem is unsolveable because one suggested solution doesn't work. But to be convincing, he'd have to demonstrate that no feasible solution can exist. --- Quote ---Shock absorbers are much smaller in diameter, not a good analogy. And you need thousands of these large diameter seals to work perffectly 24/7 to keep this system working. It's a fundamentally stupid idea from a practical engineering standpoint, when you can eliminate all that problem with existing proven tech at half the speed (MagLev) --- End quote --- It wasn't meant as an analogy, but as an example. Maybe vacuum seals really won't scale up, but then again, they don't have to scale up far, we're only talking an order of magnitude here, which feels to me like something that's difficult but far from technically impossible to do. Maybe someone with a mechanical engineering background can elaborate? And Hyperloop claim that the seals don't have to work perfectly, again they say the assume that there will be leaks. And well, calling something stupid with lots of handwaving towards various problems is stating an opinion, maybe even an educated one. But it's not really enough to be called busting an idea, imo. --- Quote ---The argument is that it seems pretty stupid to even try to manage such a system. --- End quote --- Didn't hear that, maybe because I didn't read between the lines deep enough. But hey, why not run the numbers in a back-of-the-envelope kind of way and say something like, even if you use the best available seals which have reliability x, and you have very good technicians to replace them in y time, you'd still spend more than half a day every day replacing seals, which would mean downtime for the system... yadayada. But saying "6000 seals!!!", and adding some more rethorical exclamation marks instead of an explanation isn't a very convincing argument. --- Quote --- --- Quote ---The video segments showing those interior designers: what are they doing in the video, they're supposed to show that Hyperloop consists of idea people with little background in engineering? --- End quote --- Solar Roadways have engineers. UBeam have some of the finest ultrasonic PhD's in the world. Both of these ideas will never ever work. --- End quote --- My point was: How is showing that hyperloop employs designers too furthering the unfeasibility argument? Well, it doesn't. It's ridiculing hyperloop, which whether they deserve it or not does nothing as far as busting feasibility is concerned. So why even have that scene in there at all. --- Quote ---It's technically possible if you throw money at it, but any practical engineer should be able to see all the big potential showstopper issues here. Unless you have a cool job at Hyperloop and then you have blinkers on, just like those at uBeam. --- End quote --- They are throwing quite a bit of money at it. Is it enough? Again, some back of the envelope calculations would come in handy, but someone would actually have to do them. Maybe it should be the guy that's trying to convince everyone else it couldn't possibly work. --- Quote ---But one incident will take down the entire system and likely costs lives. It's an inherent fragile engineering system. In fact it's probably the most fragile system you could come up with. Good engineering does not base itself around an inherently fragile system. --- End quote --- Most fragile? I'd probably go with airplanes for that one. They're as safe as they are because of massive overengineering. And well, yes, incidents will affect the system and kill people, that's the nature of them. Train collisions unfortunately still happen too, they kill people, they cause blockages for days, yet people still use those. --- Quote ---A door (and seals) that need to automatically open and close every 1km, at 1000kmh, do the math. This idea simply takes you further down the rabbit hole of impracticality. You are trying to come up with a solution to fix an idea that is inherently flawed. --- End quote --- I have thought about that, and it doesn't seem so difficult to do? The doors themselves could move quite slowly, and open well in advance of a car. They'd have to move just fast enough to isolate two cars from one another, pressure-wise. But really, my point is not about the hyperloop. My point is that if you claim BUSTED, you need to actually show BUSTED. And saying "Can't you see how ridiculous this is?" isn't showing anything. Doesn't have to be an airtight proof, but there have to be at least a couple of steps in that direction. And if you don't do that, I'll call it an unconvincing argument, regardless of whether I think that the claim has merit or not. |
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