Eddy currents in electromagnetic train

[Einstein44]

Homework Statement

I am currently working on a physics project, where I am experimenting with a small electromagnetic train (can look up on YouTube), which is basically a battery with magnets on either side moving through a bare copper coil.

My aim is to determine the effect on the average velocity of the train by increasing the magnetic field as I increase the magnets on the train (and therefore also its weight). Thats where I came across eddy currents and I wasn't really able to find out how it would affect this train, as I couldn't find much on eddy currents on the internet.

Now my question is if there would be eddy currents that would affect the velocity of this train as I increase the magnetic field and how it would change it, as well as how I could calculate this.

Relevant Equations

Magnitude of eddy currents: I= -1/R × dΦB/dt

Eddy Current loss: We = (Ie)^2 x Rcore
where We= Eddy current loss
Ie= Eddy Current
Re= Resistance of core

I know that the magnitude of the eddy currents is proportional to the magnetic field, which means it should increase as I add more magnets. However I am unsure if this approach is correct.

 

[berkeman]

Welcome to PF.

Can you attach some drawings or pictures of your setup? I think we will need to see it visually in order to help. Also, it sounds like your electromagnets on the train are DC, correct? Or is there a mix of electromagnets and permanent magnets?

 

[Einstein44]

The magnets I am using are permanent magnets (neodymium magnets), which become electromagnets due to the voltage from the battery they are attached to (if I am not mistaken that this would be called an electromagnet).

The way this work is that the magnets on either side of the battery touch the wire and create a complete circuit. This means electrons flow out one side of the battery, through the coil and back in the other side of the battery.
When electrons travel through a conductive wire, they generate a magnetic field. The poles of the magnetic field generated by the coiled wire are positioned so that the magnet on one side of the battery is pulled (N/S) and the other side is repelled (N/N), creating a forward motion. (please correct me if this explanation is not correct, but this should give you a better idea)

I will attach some pictures below to better visualise the setup.

 

[TSny]

A nice YouTube video