A New Simple Method to Design Degaussing Coils Using Magnetic Dipoles

Abstract

Since submarines are mostly made of ferromagnetic materials, anti-submarine warfare aircraft detect submarines using all kinds of magnetometers. In order to make the submarine magnetically silent, it is usually equipped with degaussing coils to neutralize the magnetic anomaly. However, with the increased size of the submarine, more coils are needed by conventional degaussing methods, and the degaussing system becomes complex to design and implement. To simplify the design of submarine degaussing coils and improve their degaussing accuracies, this paper presents a novel and efficient method of the degaussing coil design, which is based on the simplest equivalent model of multiple magnetic dipoles. First, the influence of the magnetic moment and spatial distribution of multi-magnetic dipoles on the equivalent effects with different spatial scales were studied. Then the simplest model of multiple magnetic dipoles was proved to capably model complex ferromagnets. We simulated the degaussing coils of a submarine by COMSOL Multiphysics software to verify the validity of the simplest modeling method and the design of the coils. The simulation results show that the magnetic anomaly induced by the submarine was reduced by at least 99% at different ranges.