Magnetic induction of ferromagnetic prolate spheroidal bodies and infinitesimally thin current bands

Baker, F. E.; Brown, Samuel H.

doi:10.1063/1.331287

Cited by 6 publications

(3 citation statements)

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“…An analytic approach may be used when the object has a spherical or ellipsoidal geometry. This technique is based on solving Maxwell's equations in a ellipsoidal coordinate system (Baker 1982). However, the use of finite element modelling (FEM) shows more accurate results when an object has a different kind of geometry (Aird 2000).…”

Section: Magnetic Field Modellingmentioning

confidence: 99%

Design of a Test Setup to Measure Magnetic Signature Reduction

Wikkerink

Mor

Polinder

et al. 2019

Conference Proceedings of ICMET Oman

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In order to avoid detection by sea mines, the magnetic signature of merchant and naval vessels can be reduced by running a current through a set of on-board copper coils. This process is called degaussing. Studies have shown that the volume, weight and energy losses of a degaussing system can be reduced by replacing the copper coils with high temperature superconductive (HTS) coils. Moreover, since the technology and production of HTS has matured and the material is highly available, the use of HTS for degaussing coils is a serious option. As a preliminary study towards an HTS degaussing test setup, this paper presents the design of a table-top demonstration with copper degaussing coils. The goal of the demonstration is to measure the magnetic signature and the magnetic signature reduction of a cylindrical object. The design choices of the test setup and the measuring system are discussed. The magnetic signature of the table-top model is calculated as well as the optimal placement of the degaussing coils and the optimal degaussing currents. These results are compared with measurements of the magnetic flux density around the demonstrator.

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Section: Magnetic Field Modellingmentioning

confidence: 99%

Design of a Test Setup to Measure Magnetic Signature Reduction

Wikkerink

Mor

Polinder

et al. 2019

Conference Proceedings of ICMET Oman

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“…Nonetheless, inclusion of -axis necessitates in the formulae with generalized functions: Finally, the inverted dyadic product gives as shown in (5). (4) For the PSCS it gives (5) as shown at the bottom of the page.…”

Section: Introductionmentioning

confidence: 99%

“…One method for modeling the magnetic field is to generate a multipole image (MI) with a classical spherical harmonic analysis [2]. However, for an elongated vehicle another type of MI, which utilizes the prolate spheroidal analysis, is more desirable [3], [4] and [5]. To simulate the external magnetic field of an elongated complex source, we use elementary sources, which include concentrated eccentric dipoles (located away from the origin) inside the spheroidal boundary and coils of Fig.…”

Section: Introductionmentioning

confidence: 99%

Multipole imaging of an elongated magnetic source

Kildishev

Nyenhuis

2000

IEEE Trans. Magn.

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This paper describes a mathematical method for modeling the magnetic field from an elongated source, a method that is relevant to the reduction of the magnetic signature of a marine vessel.We seek the magnetic multipole image (MMI), the set of coefficients in a prolate spheroidal harmonic expansion of magnetic scalar potential , which describes the magnetic source. The MMI is useful for efficient and accurate modeling of the magnetic field outside the source and for developing methods of reducing the magnetic signature.We model an elongated complex source by consideration of elementary internal sources, which consist of concentrated eccentric dipoles (located away from the origin) inside the spheroidal boundary and coils on the spheroidal surfaces (bounded by longitudes and latitudes).For the internal dipole sources, the scalar magnetic potential is expanded in prolate spheroidal coordinates in terms of associated Legendre functions. The Green function = 1 , being the distance between the source and evaluation point, is also expressed in terms of Legendre functions of the first and second kind. Since of an elementary dipole is proportional to the gradient of , comparison of the expansion coefficients is used to determine the MMI of the source. In the same way, an integration of the gradient of over the virtual surface dipoles inside the coil boundaries is used to determine the MMI of each elementary coil.Index Terms-Magnetic multipole image, magnetic scalar potential, magnetic signature, prolate spheroidal harmonic.

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First-Principal Models

Holmes

2007

Synthesis Lectures on Computational Electromagnetics

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Magnetic induction of ferromagnetic prolate spheroidal bodies and infinitesimally thin current bands

Cited by 6 publications

References 1 publication

Design of a Test Setup to Measure Magnetic Signature Reduction

Design of a Test Setup to Measure Magnetic Signature Reduction

Multipole imaging of an elongated magnetic source

First-Principal Models

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