Maglev Lift/drag Ratio

[labview1958]

Does anyone know where can I get a table regarding LIFT/DRAG RATIO for copper of thickness 1mm, 2mm, 3mm etc to 20 mm? Does the EM Lift/Drag Ratio varies with the thickness of copper? If there is no table a formula would suffice!

[Johnny5]

Does anyone know where can I get a table regarding LIFT/DRAG RATIO for copper of thickness 1mm, 2mm, 3mm etc to 20 mm? Does the EM Lift/Drag Ratio varies with the thickness of copper? If there is no table a formula would suffice!

 

What is the EM lift/drag ratio?

[[Tycho?]]

I dont know what information you are looking for, but it sounds very specific, I doubt you will find a table with those values and probably not a simple formula either.

[labview1958]

When a MAGLEV (Levitating Train) travels over Copper/Aluminum Sheet it levitates and is propel forwards. This is because there are magnets on the underside of the train. As the train moves the magnetic field CUTS the copper/aluminum sheet and a mirror image is formed in the copper/aluminium sheet. The mirror magnet and the real magnet REPELS each other. Thus the train levitates. There is EM Lift and EM Drag induced on the train. The RATIO is different for different train speeds.

 

Anyone can HELP!

[labview1958]

I am doing a STUDY of EM drag force between a moving conductor and a permanent magnet. I understand that a conductor moving with a velocity v over a permanent magnet will experience a REPULSIVE force. The formula for that force is as follows:

 

Lift force = (Mu*I*I/4*pi*h)(v*v/(v*v + w*w))

 

Drag Force = (w/v)*Lift Force

 

w=2/(mu*sigma*delta)

 

Mu = magnetic permeabilty of vacum

I = Current generated in conductor

h = separation between permagnet and conductor

v = velocity of conductor

w = charateristic velocity

sigma = conductivity of conductor

delta = conductor thickness.

 

w = The velocity where the EM DRAG is maximum

w=2/(mu*sigma*delta)

 

The formula shows that the charateristic velocity varies inversley with the thickness of the conductor. This means:

1. If thickness approaches ZERO w approaches infinity!

2. If thickness approaches infinity w approaches zero!

 

Are these deductions correct.? What part does the EDDY CURRENT penetration depth plays in this?

[CanadaAotS]

seems like the questions answered then... thicker = higher ratio

[labview1958]

Would it be right to say that for a superconductor, the conductivity is infinite? If it so than than w = 0 thus Lift force = (Mu*I*I/4*pi*h). If I put a permanent magnet on a superconductor would the lift force follow the above formula? How do I measure/calculate the current? If I know the levitation height and the weight of the permanent magnet can I calculate the current. Is this reasoning sound?

Thus mgh = Mu*I*I/4*pi*h

I*I = m*g*pi*4/Mu.

Should the levitation height of the same permanent magnet be same for ANY superconductor?

[labview1958]

Anyone still interested in discussing maglev?

[MetaFrizzics]

Me. yes I am interested in discussing it.

I was following your thread, and had a few ideas.

For one thing, you posted a formula in post #5.

 

But I suggest you look at a different version of Electromagnetic theory, namely Weber's Electrodynamics. These are just the kind of situations where the differences between theories and formulations make a difference.

Get a copy of Weber's Electrodynamics by Assis. Then we can work this problem out together perhaps.

[DQW]

Maglev is entirely understood in terms of the Maxwellian formulation of electromagnetism. Why should labview learn an entirely new formulation that is known to be wrong ?

 

Naturally, it's his/her choice, but I'd advise against it. The only point I can see in learning Weber's Electrodynamics, is to gain some historical perspective on the evolution of that area of physics in the 19th century.

[MetaFrizzics]

I won't comment on 'wrong', but perhaps it is not worth one's while to learn new material in the middle of trying to master a physical problem. Your advice is practical.

 

It seemed that no one else was interested, so I thought any interest would be welcome. In any event, I'd still be delighted to look at MagLev engineering.

 

Peace, Meta

[labview1958]

"Get a copy of Weber's Electrodynamics by Assis."

Easier said than done! I cannot find a copy where I am now! Is there a suitable website regarding that? I got my formula from a book by Mr. Moon.

[MetaFrizzics]

Sorry: Here is a link to Assis' published works and scientific articles:

 

Books and Articles by Assis

 

Buy on Amazon

Book Description

This volume is a substantially complete presentation of the electrodynamics developed by Wilhelm Weber. Weber's force between point charges is explored and thoroughly analysed. Ampère's force between current elements is discussed in connection with modern experiments relating to the Ampère versus Grassmann--Biot--Savart controversy. Ampère's force is a central feature of this work, as Maxwell maintained it should always be in the study of electrodynamics, although it is included in few textbooks on electromagnetism. A detailed study of this force is an outstanding feature of this book. Other topical questions of physics are analysed, such as a potential-dependent inertial mass, Mach's principle and the origin of inertia, action at a distance as opposed to contact actions, etc. No previous knowledge of the subject is required, and all topics are introduced with both their historical backgrounds as well as modern experimental evidence. This volume will appeal to physicists, mathematicians, electrical and electronic engineers, historians and philosophers of science.

I hope this helps. I can probably find other material more easily suited to MagLev as well.

[labview1958]

I am interested in the following formula regarding MAGLEV. It is a relationship between drag force and lift force.

 

Drag Force=k*Lift Force

where k = ω/v and ω = 2/(μσ Δ)

 

• where μ = permeability of free space

• v = velocity of conductor/magnet

• σ = conductivity of track

• Δ = thickness of conductor

ω = characteristic velocity

 

I have run an experiment on copper and I found that the characteristic velocity found by experiment is twice the calculated value. Since ω = 2/(μσ Δ)

and (μσ Δ) is a constant, how can that be?

 

Is the standard formula given in textbooks wrong? Where can I get more experimental data regarding MAGLEV?

[arkain101]

You can elminate the drag by having switches on elctro magnets, either on the rail or the train one of the two. To only have a pulling force.

[labview1958]

A correction

 

Drag Force=k*Lift Force

where k = ω/v and ω = 2/(μσΔ)

 

• where μ = permeability of free space

• v = velocity of conductor/magnet

• σ = conductivity of track

• Δ = thickness of conductor

ω = characteristic velocity

 

Where to get additional experimental data?