Multiphysics model for predicting the sound radiation of a single-layer air-core coil

Abstract

Due to environmental standards, noise reduction solutions for high voltage devices such as dry-type air-core reactors are needed. The objective of this paper is to predict the vibroacoustic response of a single layer air-core reactor from its electrical feed to its acoustical response. Since the coil is a non-ferromagnetic powered conductor placed in a field created by itself, the excitation accounted for is the Lorentz force. The presented multiphysics model couples electromagnetic, mechanical and vibroacoustic numerical softwares. The electromagnetic model gives the distribution and the amplitudes of the Lorentz forces applied on the mechanical structure of the coil. The mechanical model determines the normal modes of the coil on which the Lorentz forces are applied. Finally, a modal vibroacoustic response is performed. The final and intermediate numerical results are compared to experiments performed on a prototype coil normally intended for the manufacture of loudspeakers, showing a good agreement.