Asymptotic Analysis of Magnetic Induction with High Frequency for Solid Conducteurs
Abstract
In this paper we describe the behaviour both in time and in space of an induction field created by an imposed high frequency alternating current around a solid conductor. To do this, we introduce two time scales and we decompose the induction field in a mean field and an oscillating field. With the help of singular perturbations theory and multiple scales method we obtain two uncoupled models; one for the large time scale and the other for the high frequencies. For a cross section of a solid column of metal, we build the two first terms of the asymptotic expansion of the induction field. Moreover, we justify the classical harmonic approximation used in such configuration. Finally in the case of a cylinder column, we apply the previous results by computing numerically the induction for different values of the frequency.