Green high speed train - unlike any train you've seen before
High Speed Trains such as the Bullet Train (Shinkansen) in Japan, the Frech TGV or Germany's ICE surely don't produce any fumes when running, but they devour a lot of electricity. Because this power doesn't always come from the best renewable sources, some scientists at Tohoku University in Japan are trying to reduce the energy these machines need to run.
They have come up with an interesting idea: using ground effect to raise the train a few inches from the ground and hece reduce all losses of power from ground friction. The train becomes then a ground version of the USSR's ekranoplan which used the same principle over water.
So far, the prototype weighs 400 kg (about 900 pounds) but reaches 150 km/h (90 mph). The ground effect is produced when a vehicle, at certain speeds, creates a difference of pressure between the air that flows underneath and over the vehicle. While sports cars try to reverse the effect to keep the wheels on the ground to gain adherence, this train seeks the opposite: raising itself so friction is reduced. The scientists claim that energy use with this floating style is dramatically lower than maglev trains, where a lot of power is needed to maintain the magnetic fields that sustains the train.
What's even more interesting is that this prototype uses power from windmills and photovoltaic panels installed along the same track where it hovers to make it a really sustainable transport method.
[Source: El País]
Reader Comments (Page 1 of 1)
Jerzy 4:50PM (4/28/2008)
A similar, and more practical concept, called AirTrain, can be seen at: http://www.airtrainglobal.com/index2.html
Another tracked air-cushion train (TACV) has been developed in France and the US.
http://www.shonner.com/aerotrain/index.htm and http://www.aerotrain.net (French history)
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Joseph George 11:35PM (11/10/2008)
The same concept can be seen in the following website from 2004:
http://www.geocities.com/newideasfromtelewise/wingtrain.htm
and one more website
http://www.physics-edu.org/tech/wing_levitated_ground_effect_train.htm
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Joseph George 11:52PM (11/10/2008)
Ground effect train: Origin of concept 2002, internet publication 2004.
you can find more technology ideas from
http://www.geocities.com/newideasfromtelewise/Inventions_Innovations.htm
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Matt 8:40AM (11/09/2007)
I see one drawback here, that wide track is going to use a lot of land, looks approx 3/4 times the width of standard rail line and no doubt it'll be concrete, bang go all the benefits.
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scatter 8:52AM (11/09/2007)
I wouldn't write it off to quickly Matt. A ducted wing in ground effect craft would need very small amounts of energy to propel itself. Governments seem all too keen to build new, large motorways which take up even more space and have inefficient cars and trucks operating on them. While the embodied carbon of concrete is high, the lifetime is long so the reduction in operational carbon emissions could quite possibly produce benefits.
It's an intriguing concept certainly.
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Chris M 1:50AM (11/11/2008)
Um, I hate to point it out, but this would be wider than most freeways, and carry far less traffic!
Dave Schmetterer 10:07AM (11/09/2007)
Where is the difference between this and flying - slowly, and at low altitude. Sure, this has its own right of way - but so does BRT, PRT, and all the different forms of rail transit.
The way I understand it, ground effect is when air is caught between the wings and the ground, keeping the plane off the ground. Isn't that just another way of saying drag?
At first blush, this looks like a system of PRT (personal rapid transit) that used small planes hanging on monorail track. As the vehicle sped up, the planes produced a small amount of lift, which reduced friction with the track.
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Evan 1:56PM (11/09/2007)
Um last I checked, this type of vehicle is called a plane...
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GoodCheer 2:12PM (11/09/2007)
Dave: As I understand it, ground effect both increases lift and reduces drag (the forces due to air acting on the wing the backwards and upward directions respectively). Lift in increased because the air being pushed down by the wing has nowhere to go, so the pressure on the underside of the wing is higher than it would be far from the ground. The drag is reduced because the nearness of the ground inhibits the formation of tip vortices at the end of the wing.
It does seem like the added real estate needed for the wide track would be hard to justify even a fairly large improvement in efficiency. I just don't think energy is a very significant fraction of the cost of operating a train.
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Nils 2:15PM (11/09/2007)
It will be too expensive to build because of its large footprint and the huge quantities of concrete needed. Furthermore, I can't see any advantage over a maglev train. Remember maglevs like the German Transrapid are way more efficient than conventional trains because of a number of reasons, not the least being the fact they don't need to carry their own propulsion (the track IS the motor) and thus are very light which in turn reduces the need for a lot of power to move the whole thing. That's why maglevs can accellerate at a rate 5-6 times what a train can achieve. This concept needs to carry a lot of motors that move air in a very inefficient way (fans/propellers) and how will the motors be fed electricity? Perhaps with a sort of bogey or skid? Not very drag free if you ask me...
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rgseidl 2:27PM (11/09/2007)
@Matt -
agreed, that concrete track is a deal-breaker right off the bat. The cost of the concrete construction is one issue, but securing ownership of a sufficiently wide swath of land hundreds of miles long is an even more daunting proposition.
The one context in which ekranoplan technology could be commercially viable is low-cost passenger and light freight service along river systems, even when they are frozen over in winter. Sparsely populated flat grasslands, deserts or snow fields might also be candidates. In any case, propulsion would have to come from turbodiesel engines. Anything else would just be outlandishly expensive to construct and/or operate.
For safety, the craft would have to be capable of landing and maneuvering on water, even if the normal MO is to use land-based airfields. It would also need to support a conventional flying mode in case the water gets choppy or winds make low-level flying too dangerous. The price for this will be additional power and fuel consumption plus fancy electronic control systems to keep the craft stable.
Water-borne take-off also requires a lot of additional power, typically one or more additional engines that can be turned off during cruising. Flying extremely low over other types of terrain would introduce different safety requirements, e.g. a very rugged and compliant landing gear with large balloon tires and/or skids.
Finally, civilian applications would need redundant radio and/or satellite uplinks so they can always transmit their location to air traffic control - flying below 50 feet, radar won't pick them up.
In any case, designers should focus on a simple craft before they even consider articulated contraptions.
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Peter 11:55PM (11/09/2007)
Hi.
Potential of speed is limited.
technology based on magnetic levitation will be able to reach unexpected speeds in vacuum tunnels.
Without air resistance {which could't be reality in case of project of Tohoku University} maglevs will definitely consume less energy than airsrews.
Not talking about electric propulsion technology, which will remove driving mechanism of maglev from its track to train itself.
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Chris M 1:51AM (11/10/2007)
One safety concern would be an unexpected gust of wind increasing lift and literally blowing it off the tracks.
As for it being more efficient than maglev, they are half right. Attractive maglevs using electromagnets (Transrapid) do consume a lot of electricity for levitation, but inductive levitation using permanent magnets (Inductrac) is "powered" by forward motion and has very low drag - much lower than the drag caused by the wings and propellers of a ground effect train.
Come to think of it, there have been proposals for air cushion trains that would ride on a much narrower track, and might actually be a more energy efficient method of "air levitation".
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Matt 9:35AM (11/12/2007)
Just to follow up my first comment, I understand very well what the ground effect is as I have a degree in aeronautical engineering but it's one of the news items which is so 'never going to happen' I wonder what the motive is for publishing it is. I mean Japan of all places, they have loads of spare flat land don't they. Don't get me wrong I'd go for a more expensive long term more efficient solution every time, but there are limits.
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