Hyperloop UPV Design

[Fungus]

The entire concept of the Hyperloop is based on the vacuum premise 

This is our concept train. Does that big fan on the front look like it's designed for a vacuum? 



It'll be low pressure air, yes, but not vacuum. Vacuum causes all sorts of side effects, eg. cooling of all the massive electromagnets and batteries. What you need is a balance between air friction and not cooking the people/goods inside to medium rare.

[EEVblog]

The entire concept of the Hyperloop is based on the vacuum premise 

This is our concept train. Does that big fan on the front look like it's designed for a vacuum? 

No, and that's not a bad idea.
But how on earth did that concept even get off the back of the envelope?
What does it actually ride on?
I presume the force air, but what happens when the speed isn't high enough for that? Rollers? Rails is just slids on? does it just suddenly plonk on the ground when the speed goes down?
What stops it from spinning?
I like the concept of compressed air sucked in the front, possibly used for (or or some) lift, and pushed out the back, that could work. But this tubular design looks completely flawed. There seems to be no practical considerations put into this? 

[Fungus]

What does it actually ride on?

It hangs from the ceiling, on magnets.

What stops it from spinning?

The same thing that stops ships rolling over at sea.

[EEVblog]

What does it actually ride on?

It hangs from the ceiling, on magnets.

Ok. Suspended Maglev.
Why the top and not the bottom?
What about the sides or bottom? How do you prevent it from slamming into the side of the tunnel when it goes around the slightest bend?
(and what is the maximum bend radius?)
Do you have a web site or something detailing this design?

[Fungus]

What about the sides or bottom? How do you prevent it from slamming into the side of the tunnel when it goes around the slightest bend?

All the magnets are in the top of the train so it can 'bank' under inertia. There's electromagnets in the sides to keep it the center of the tube.

(and what is the maximum bend radius?)

TBD.

Do you have a web site or something detailing this design?

http://hyperloopupv.com/

[Fungus]

So why are the test tracks obviously designed to be vacuum sealed with inches think port windows and complete welds?

Because ... that's the original Sci-Fi dream. It's what the press likes writing about. 

I presume you agree that is a complete waste of time and money?

Me personally? Yes. Other teams may be aiming for that but that's their problem.

I think there's a balance to be found between reduced air pressure/friction and practicality.

[EEVblog]

http://hyperloopupv.com/

Where have you tested this?

[EEVblog]

What about the sides or bottom? How do you prevent it from slamming into the side of the tunnel when it goes around the slightest bend?

All the magnets are in the top of the train so it can 'bank' under inertia. There's electromagnets in the sides to keep it the center of the tube.

[EEVblog]

Full design doc (well, Jan 2016 anyway):
https://drive.google.com/file/d/0B0HPI9kbOr9IelNQcXdJOU5weFE/view

[Z80]

I'm not seeing the point of hanging suspension in this case?  If it's just to be different as a concept then ok but a practical design would need to fail safe.  I had a quick read through the original design concept summary on Wikipedia  and didn't see anything too wrong with the concept.  They talk about reduced pressure (because high vacuum would be stupidly impractical) and cars suspended by air bearings, pumped & aerodynamic which gives you fail safe.  Still a challenge to actually get working at anything like the speeds they are talking about and although the concept isn't that remarkable, the devil is always in the detail.  The biggest question is what are they trying to solve, the problem with air travel is the politics & ludicrous scare mongering, the actual flight times would match this idea.

[Fungus]

http://hyperloopupv.com/

Where have you tested this?

We haven't, yet. We don't actually have a tube to test anything like that.   

The way hyperloop works is that each year there's a challenge for the teams to complete. Last year's challenge was to build a single passenger pod and make it go down a tube on a rail.

The 'years' follow the academic timetable, ie. They start in September. Our tube is being installed as I write this so this year will be all about trying to levitate something inside it. Other teams have more money so they already had a tube last year. So it goes.

[EEVblog]

I presume you agree that is a complete waste of time and money?

Me personally? Yes. Other teams may be aiming for that but that's their problem.
I think there's a balance to be found between reduced air pressure/friction and practicality.

Why is your design only 100Pa then?
That's practically a complete vacuum just like the others, 1/1000th of typical sea level air pressure of 100kPa.
It's in your design document:

[Fungus]

I'm not seeing the point of hanging suspension in this case?

To me it seems easier than trying to push it up from underneath. Gravity works with you to keep it stable, not against you.

If it's just to be different as a concept then ok but a practical design would need to fail safe.

There's 10^6 problems to be solved, yes. We don't have all the answers yet.

[Fungus]

Why is your design only 100Pa then?

I wouldn't put much faith to in the numbers in that document. The confidence of amateurs is the envy of professionals, etc.

Not everybody believes the things I say in meetings, I'm just an old fart so what do I know? 

That's practically a complete vacuum just like the others, 1/1000th of typical sea level air pressure of 100kPa.

Numbers change rapidly when they start to build things. The last numbers I heard being thrown around in the meetings were 1/10th of an atmosphere. That might change, too.

[Fungus]

Maybe I should be more clear that I don't speak officially for the team or anything like that.

We make plenty of documents and press releases, etc., but the engineering is still mostly up in the air.

I can't give any definite answers on specifications or on how many magnets will be in it. We have to build a train first.

Our team is also about to change completely because a lot of the students were in their final year and have left University. We're currently interviewing for this year's team.

The main point is that I don't think Hyperloop is completely crazy and if anybody can do it, Elon Musk can

[EEVblog]

The main point is that I don't think Hyperloop is completely crazy and if anybody can do it, Elon Musk can

But he's not doing it. He does not own any Hyperloop company, nor is he even a director of any Hyperloop company that I know of. And AFAIK, apart from Space-X sponsoring a few student contest things etc, he doesn't have skin in the game at all.
People think he's doing it, but he's not, and it's a big secret no one seems to want to mention.
All everyone sees in the press is "Elon Musk's Hyperloop", so they automatically equate it with his Space-X, Tesla, and Solar City companies. Nothing could be further from the truth.

[StillTrying]

Where does the driver sit?
Make a model to work in a 8 inch pipe, to prove how impractical it is.

[Kleinstein]

Something in the 100 Pa range is completely plausible. This is what you can easily get with mechanical pumps but still more in the range of classical aerodynamics and not yet molecular dynamics. With a higher gas pressure there would be likely too much pressure build up in front. It might still be enough to use aerodynamic lift with the increased pressure in the thin gap. At the planed speed there is not just one pressure, but different pressures in front, in the gap and at the back.

I am not so sure about the speed - there could be tricky effects getting close and beyond the speed of sound in some areas. Also the speed of sound can change with gas composition, e.g. water contend - at such a low pressure you can no longer assume normal air composition, as pumps work different with different gases and leaks can be gas specific too. In high vaccum systems there is usually a higher fraction of water, hydrogen and helium than in normal air composition.

A smaller scale model would be a logical step - most of the problems could probably be tested at smaller scale. There won't be a passenger inside for quite a while anyway. However magnetic levitation might get more difficult on small scale (magnetics tend to work better in large scale).

If magnetic levitation is planed, I would consider both top and bottom - this would help keeping it not as unstable. The attractive part gets stronger the shorter the distance - thus an inherently very unstable system. At least the magnetic levitation system is well proven, so nothing fully impossible. 

[StillTrying]

To get all of the air from in front of the train to behind the train, through the train's small internal tube, the compressor is going to have to increase the low air pressure by about 300 times. I don't think this would be possible even if the whole train was just compressor!

[Fungus]

If magnetic levitation is planed, I would consider both top and bottom - this would help keeping it not as unstable. The attractive part gets stronger the shorter the distance - thus an inherently very unstable system. At least the magnetic levitation system is well proven, so nothing fully impossible.

Another problem is the ratio of permanent to fixed magnets. If there's too many fixed magnets there's a danger of losing control and slamming into the top of the tunnel. If there's a lot of electromagnets then the power/battery requirements go up massively and become a limiting factor in the distance you can travel.

We'll see how it goes.

[Fungus]

To get all of the air from in front of the train to behind the train, through the train's small internal tube, the compressor is going to have to increase the low air pressure by about 300 times. I don't think this would be possible even if the whole train was just compressor!

Yep. It's a problem. We need to figure out how much air we can get past/through the train.

Also if the air can be used to any advantage, eg. to provide some lift.

There's no shortage or problems to solve.

[tszaboo]

High energy efficiency

How much energy does it take to operate the pumps for the air. Nobody knows. And you need to do that if there is 1 train in the tube, at night, where there is nobody travelling.

Fully autonomous

Yeah, autonomus metro is solved in 1983.

100% Electric

Well, no kidding here. Train is electric.

Rail-free, savings in infrastructure

So you replace about 70KG/m rail with a tube, and expect cost saving. Aham. Not to mention, you need electricity in the train, so you will eventually need an extra rail or two (doh) to carry the electricity to it.

The thing is, I like the idea, I dont like bullshit. Write: We do it, because it is awesome, and someone else is paying for it.

[MrW0lf]

There's no shortage or problems to solve.

Given couple B$ to spend think could also come up with some nasties taking extra long to solve...

[CJay]

You're all wasting your time, Hyperloop is dead.

Elon is now planning to fire commuter rockets between cities, I think Kim Jong Un is an early adopter.

http://www.bbc.co.uk/news/science-environment-41441877

[Fungus]

You're all wasting your time, Hyperloop is dead.

Elon is now planning to fire commuter rockets between cities, I think Kim Jong Un is an early adopter.

Around here we mostly talk about cargo, not people, so...