Paul1999

To calculate theoretical eddy current braking, the length of the conductor does not matter (an infinite plate between the poles of the magnet is usually used), but its thickness and the source of the external magnetic field matter, and in my case they have a finite geometry. So I think I can use "dimensionally closed" equation, but thanks for Your advice.

I try to calculate brake force for a primitive eddy current brake. The idea is that when a magnetic flux passes through a conductor (copper tube), it excites eddy currents, which are the source of the magnetic field, which is oppositely directed with respect to the external field, thereby generating a braking force. I found the equation for the braking force, which is calculated through power losses, and derived the expression for power losses. But I don't know how to determine the frequency (а) for calculating the skin effect (б), because I use direct current (eddy currents are excited by a quasi-alternating magnetic field). I also can't decide what to use as the characteristic length (lh) for the magnetic Reynolds number (Rm). I assume that it could be the diameter of the copper tube or the length of the area through which the magnetic flux passes.