We present a calculation in a simplified geometry for the current distribution in the rails, taking into account the motion of the armature and the time variation of the current. Closed form, asymptotic, results for the current density are obtained for arbitrary time dependent currents and velocities, in the limit in which the length scale k0- = (μ0σv), σ is the electrical conductivity of the rails, and v is the speed of the armature. Because of eddy current effects the rail current may reverse in portions of the rails when the total current decreases. The current is used as a source of Joule heating to find the temperature distribution in the rails. The heat diffusivity is negligible and we are able to give numerical results concerning melting.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering