Abstract
A dimensionless analysis of eddy current distribution on massive conductors was undertaken, using configurations for two excitation sources co-axial to a cylindrical induction device: a solenoidal type, as found in most coreless furnaces, and an axial type, similar to that used in induction motors. The mathematical model is based on a one-dimension solution of the electromagnetic diffusion equation in an infinitely long cylinder utilizing the Newton shooting method. The simulated electromagnetic performance is compared for both configurations for a minimum in either the operational frequency or the size of a given induction heating system. The theoretical results show that workpieces powered by single-phase axial winding, featuring one pair of magnetic poles, release ohmic losses equivalent to the solenoidal counterpart using half of its frequency or the square root of its radius.
