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waterway

cheap maglev
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Jim reckons maglev is expensive - and might be the reason people used horse drawn boats running in water filled canals instead…

He also figures the physics have not changed.

Jim proposes a magnetic field strong enough to attract a thin layer of saline to the surface of a train. The said vehicle can then be drawn along an empty ((edit) not dry) canal as if it was water filled.

Sneaky…

madness, Oct 22 2011

how to do it http://en.m.wikiped...agnetohydrodynamics
belive it or not [madness, Oct 22 2011]

[link]






       Po check out the link (feel free to delete your comment) because I am about to…
madness, Oct 22 2011
  

       Max has a horrible feeling that the viscous drag on the train will be far greater than the rolling friction of wheels. He also thinks that this idea is evolutionarily convergent with a slug.   

       He does, however, think it's ingenious. If he can ever meet this Jim chap face to face, he would give him a bun.
MaxwellBuchanan, Oct 22 2011
  

       Too complicated; why use magnetohydrodynamics (yes, I believe it, as does anyone else who has ever A) wondered if Tom Clancy was full of $#!+ or B) seen or read about that Japanese MHD-drive boat) when the train could just as easily work by simple capillary action?
Alterother, Oct 22 2011
  

       What [po] said.
Alterother, Oct 22 2011
  

       Is Jim is not capable of posting his own ideas?   

       Or is Jim being set up as a scapegoat?
Twizz, Oct 26 2011
  

       Slow-moving boats are great, because water has no limiting friction, but drag increases with the square of velocity. And with a thin layer of liquid, and massive shearing forces, drag is going to be substantial.   

       The train won't float, as such; its weight is not counteracted by buoyancy due to displacement. Instead, the liquid is acting as a lubricant. So why not use a ferrofluid, or an oil ?   

       Maintaining ride height and stability will be ... challenging.   

       Jim needs to make sure he takes his meds regularly.
8th of 7, Oct 26 2011
  

       What [Master Quest] said.
Voice, Oct 26 2011
  

       As others have said, this would not work to float a vehicle, the best you could hope for is a hydrodynamic lubrication, but that only works by letting some of the fluid trail of the back. You could then use magnetohydrodynamics to pull thr fluid around to the front.   

       At that point, however, you will find it far more effecient to simply put wheels on the vehicle.
MechE, Oct 26 2011
  

       Saline solution was presented because it is a natually occuring organic compound. I agree that there is likely to be a better inorganic compound.   

       //This would mean carrying a large supply of saline in on-board tanks, and at that point you've lost all chance of gaining any efficiency.   

       Not really --- the fluid supporting the train can be gathered from the water way itself. Only a small amount of saline needs to be present, just sufficient to 'wet' the surface.   

       //the best you could hope for is a hydrodynamic lubrication, but that only works by letting some of the fluid trail of the back.   

       Again not really --- the amount of fluid trailing out the back will be small and constantly replenished.   

       //At that point, however, you will find it far more effecient to simply put wheels on the vehicle.   

       Obviously I disagree :)   

       I think the analogue here is that of an ice skate. Which is to all intensive purposes frictionless. The pressure of the skate on the ice melts/creates a tiny bead of water which will trail behind the skater.   

       Here, energy is required to gather and maintain such a bead of water under the train. The amount of energy required is small compared to that required to levitate. Which is why ice skates and this idea work so well...
madness, Nov 03 2011
  
      
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