Eddy current induction in a solid conducting cylinder with a transverse magnetic field

Quasistatic magnetic field solutions for a right circular cylinder of arbitrary conductivity and permeability immersed in a uniform transverse magnetic field are considered. The cases of a rotating cylinder in a dc magnetic field and a stationary cylinder in an ac magnetic field are included. The solutions are described in terms of the magnetic Reynolds number, a dimensionless quantity which indicates the effect of dynamics on the magnetic field inside the conducting cylinder. The field distributions are plotted over the complete range of dynamic behavior using known approximations to ber and bei functions. To verify the theoretical results, experiments are performed to measure changes in the magnetic field outside a conducting shaft as a function of shaft rotation speed or magnetic field frequency. These measurements are correlated with the calculated solutions for the magnetic flux density outside the conducting cylinder. An external magnetic Reynolds number is found to be an appropriate indication of the change in magnetic field outside the conducting cylinder.