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View Poll Results: Which form of HSR will own the 21st. century?
Conventional - wheels on rails 163 52.24%
Maglev - magnetic levitation 116 37.18%
Horse drawn rail cars ^_^ 33 10.58%
Voters: 312. You may not vote on this poll

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Old November 3rd, 2010, 02:18 PM   #121
K_
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Quote:
Originally Posted by SamuraiBlue View Post
Auhh, do you really understand what you are talking about?
Yes I do. I'm a civil engineer.

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Gravity is a constant force pulling you to the center so you need constant force in the opposite direction so maintaining at a certain height requires a constant amount of energy.
Again, force is not the same as energy. Where is the "constant amount of energy" keeping the floor in the building where I work at a constant coming from?

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You also have not addressed the fact that to accelerate you need energy and the amount of energy is dictated by the amount of mass so lighter the mass the less energy is required.
We were talking about levitation.

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The JR maglev system is not like the Transrapid system, it maintains lift through Electro-dynamic Suspension(EDS), EDS has the advantage of larger gaps than Electromagnetic Suspension (EMS), but EDS needs support wheels which are employed in low speed running, because EDS can't produce a large levitation force therefore in part utilizes a phenomenon known as wing ground effect where at a certain speed the constant air rushing underneath blows up the body like a gust of wind blowing up fallen leaves. Not enough energy to lift it completely but with EDS working together it lift and stabilizes the train at speed above 150Km/h.
I know the difference. Inductrack is also an EDS system, but using permanent magnets. In this maglev system there are no powered magnets used at all to lift the vehicle. Yet levitation does cost a small amount of energy (as we are not in a perfect world), can you guess where it shows up?
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Old November 3rd, 2010, 02:37 PM   #122
SamuraiBlue
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Originally Posted by K_ View Post
Again, force is not the same as energy. Where is the "constant amount of energy" keeping the floor in the building where I work at a constant coming from?
We were talking about levitation.
Yes we are talking about levitation now where is the floor?
Without the floor you go into free fall, no?
If supporting beams of the floor is not strong enough again the floor will collapse, no?
Force is energy with vector, force of gravity is a energy force with a vector toward the center of mass, as I have written you need constant force opposite with a vector opposite of gravity with enough energy to cancel gravity to sustain levitation.


Quote:
Originally Posted by K_ View Post
I know the difference. Inductrack is also an EDS system, but using permanent magnets. In this maglev system there are no powered magnets used at all to lift the vehicle. Yet levitation does cost a small amount of energy (as we are not in a perfect world), can you guess where it shows up?
Auhh, JR maglev EDS systems do not use permanent magnets for one thing.
What you call inductrack is magnetic induction meaning a coil obtains electro-magnetism through a strong magnetic force that passes by. The intensity of the coil's magnetic field induced depends on the speed and the strength of the magnetic field passing by. The passing magnetic field is generated by the super conductive magnets within the train.

Last edited by SamuraiBlue; November 3rd, 2010 at 02:48 PM.
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Old November 3rd, 2010, 05:00 PM   #123
K_
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Originally Posted by SamuraiBlue View Post
Force is energy with vector, force of gravity is a energy force with a vector toward the center of mass, as I have written you need constant force opposite with a vector opposite of gravity with enough energy to cancel gravity to sustain levitation.
You need a force, but please, stop confusing force with work. If you generate a magnetic field that does no work, then the only electrical energy consumed will be to counteract internal resistance.
Once you do perform work with your field ofcourse you need to provide more energy. However work is only performed when the force moves an object, not when it is keeping an object in place. SO in the context of a maglev the "work" done consists of the initial levitation, and in an active system the control of the field. But nto a lot is needed. The Transrapid for example needs less energy to maintain its levitation than it needs for its air conditioning, and can hover for an hour on batteries alone.

You can produce a magnetic force using a permanent magnet. There no energy is consumed, yet heavy weights can be kept in place against gravety...


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Auhh, JR maglev EDS systems do not use permanent magnets for one thing.
I didn't say it did.

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What you call inductrack is magnetic induction meaning a coil obtains electro-magnetism through a strong magnetic force that passes by. The intensity of the coil's magnetic field induced depends on the speed and the strength of the magnetic field passing by. The passing magnetic field is generated by the super conductive magnets within the train.
Indeed. And the magnetic field doesn't come cheap. There is a "magnetic drag" which basically means that part of the forward impulse of the vehicle is consumed to generate the currents in the track that create the field. This magnetic drag generates lift. However inductrack has a very good lift/drag ratio so not a lot of the energy put in the system is used for levitation. (more like 1% or so).
Transrapid needs more energy for maintaining levitation, but that is mostly because it is an active system, constantly adjusting the fields to keep the air gap constant. That costs energy, but still only about 10% of the total energy needs of the system.
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Old November 3rd, 2010, 06:49 PM   #124
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Originally Posted by K_ View Post
You need a force, but please, stop confusing force with work. If you generate a magnetic field that does no work, then the only electrical energy consumed will be to counteract internal resistance.
Once you do perform work with your field ofcourse you need to provide more energy. However work is only performed when the force moves an object, not when it is keeping an object in place. SO in the context of a maglev the "work" done consists of the initial levitation, and in an active system the control of the field. But nto a lot is needed. The Transrapid for example needs less energy to maintain its levitation than it needs for its air conditioning, and can hover for an hour on batteries alone.
Why do you change your wording? It was force now it is work.
No there is no work done after it obtains a certain height and it remains at the same height but gravity is constantly WORKING against mass so an equal force is required in opposite vector to maintain at the same height.
Why do you come to a conclusion that it does not need a lot?
Again Transrapid system is a completely different technology that DOES use permanent magnet.
And again you are still neglecting the fact that more mass requires more energy to achieve acceleration so heavy bogies on maglev is completely useless.
If more mass is added to JR maglev it will require higher speeds to achieve levitation to obtain the necessary strength in the induced magnetic field.


Quote:
Originally Posted by K_ View Post
Indeed. And the magnetic field doesn't come cheap. There is a "magnetic drag" which basically means that part of the forward impulse of the vehicle is consumed to generate the currents in the track that create the field. This magnetic drag generates lift. However inductrack has a very good lift/drag ratio so not a lot of the energy put in the system is used for levitation. (more like 1% or so).
Transrapid needs more energy for maintaining levitation, but that is mostly because it is an active system, constantly adjusting the fields to keep the air gap constant. That costs energy, but still only about 10% of the total energy needs of the system.
Again you mixing technology.
The JR system feeds electricity into the primary electromagnetic motion coils constantly switching polarity to move the train forward. The train's super conductive magnets repel/contract the primary magnetic field while generating another magnetic field within separate levitation coils embedded in the fence covers as it speeds down the guide way to levitate the train. The secondary levitation field is generated through the Meissner effect so I do not think any energy is lost.
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Old November 3rd, 2010, 11:27 PM   #125
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I hope India, Pakistan, Brazil, Mexico, USA, Australia, Japan, China, Russia, Indonesia and Canada will invest in Maglev.

In particulary the vactrain version.

I'd also like to see a Maglev line Berlin - Munich.

MAGLEV FOR AFRICA!
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Old October 1st, 2012, 06:07 AM   #126
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Parts 2→5:

https://www.youtube.com/watch?v=4i9pYhctjBY

https://www.youtube.com/watch?v=EiVNDKOn714

https://www.youtube.com/watch?v=N1wqDZ51Is0

https://www.youtube.com/watch?v=qP0H-KAt94Y

The SC search tool seems broken, I can't tell if (any of) this programme's been shared yet ...
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hee hee
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