2D and 3D numerical modeling of experimental magnetization cycles in disks and spheres

Farinon, S.; Iannone, G.; Fabbricatore, P.; Gambardella, U.

doi:10.1088/0953-2048/27/10/104005

Cited by 18 publications

(16 citation statements)

References 22 publications

(35 reference statements)

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“…There are many 3D modelling methods for superconductors, such as Finite Element Methods, FEM, and variational methods. There are several formulations of FEM like the H-formulation [4], [5], [6], A − φ vector and scalar potential [7], T − Ω current and magnetic formulation [8] or H formulation with homology-cohomology [9]. A completely different approach represents the variational methods.…”

Section: Introductionmentioning

confidence: 99%

Demagnetization of Cubic Gd-Ba-Cu-O Bulk Superconductor by Crossed-Fields: Measurements and Three-Dimensional Modeling

Kapolka

Srpcic

Zhou

et al. 2018

IEEE Trans. Appl. Supercond.

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Superconducting bulks, acting as high-field permanent magnets, are promising for many applications. An important effect in bulk permanent magnets is crossed-field demagnetization, which can reduce the magnetic field in superconductors due to relatively small transverse fields. Crossedfield demagnetization has not been studied in sample shapes such as rectangular prisms or cubes. This contribution presents a study based on both 3D numerical modelling and experiments. We study a cubic Gd-Ba-Cu-O bulk superconductor sample of size 6 mm magnetized by field cooling in an external field of around 1.3 T, which is later submitted to crossed-field magnetic fields of up to 164 mT. Modelling results agree with experiments, except at transverse fields 50% or above of the initial trapped field. The current paths present a strong 3D nature. For instance, at the mid-plane perpendicular to the initial magnetizing field, the current density in this direction changes smoothly from the critical magnitude, Jc, at the lateral sides to zero at a certain penetration depth. This indicates a rotation of the current density with magnitude Jc, and hence force free effects like flux cutting are expected to play a significant role.

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Section: Introductionmentioning

confidence: 99%

Demagnetization of Cubic Gd-Ba-Cu-O Bulk Superconductor by Crossed-Fields: Measurements and Three-Dimensional Modeling

Kapolka

Srpcic

Zhou

et al. 2018

IEEE Trans. Appl. Supercond.

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“…In addition, the parallel development of numerical codes allowed addressing complex problems, such as the distribution of the current density and of the induction magnetic field inside superconductors of several geometries [15][16][17][18], even in presence of other materials with nonlinear magnetic properties, such as ferromagnets [14,[19][20][21]. Several methods have been proposed for the superconducting modeling [15,22] where the problem is expressed in terms of the field variables (e.g.…”

Section: Introductionmentioning

confidence: 99%

Superconducting and hybrid systems for magnetic field shielding

Gozzelino

Gerbaldo

Ghigo

et al. 2016

Supercond. Sci. Technol.

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In this paper we investigate and compare the shielding properties of superconducting and hybrid superconducting/ferromagnetic systems, consisting in cylindrical cups with aspect ratio height/radius close to unity. Firstly, we reproduced by finite element calculations the induction magnetic field values measured along the symmetry axis in a superconducting (MgB 2) and in a hybrid configuration (MgB 2 /Fe) as a function of the applied magnetic field and of the position. The calculations were carried out using the vector potential formalism, taking into account simultaneously the non-linear properties of both the superconducting and the ferromagnetic material. On the basis of the good agreement between the experimental and the computed data we applied the same model to study the influence of the geometrical parameters of the ferromagnetic cup as well as of the thickness of the lateral gap between the two cups on the shielding properties of the superconducting cup. The results show that in the considered non-ideal geometry, where the edge effect in the flux penetration cannot be disregarded, the superconducting shield is always the most efficient solution at low magnetic fields. However, a partial recovery of the shielding capability of the hybrid configuration occurs if a mismatch in the open edges of the two cups is considered. On the contrary, at high magnetic fields the hybrid configurations are always the most effective. In particular, the highest shielding factor was found for solutions with the ferromagnetic cup protruding over the superconducting one.

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“…Research on the simulation of the HTS problem has typically focused on the application side, and has considered moderate scale test cases with commercial software implementations of linear (at most quadratic) edge elements; see, e.g., [11,37,38]. On the other hand, 3D problems are of high interest in HTS modelling [3,5,11,39,40], but far from being at the maturity level as one can find in 2D, due to their high computational complexity and the poor (parallel) scalability of commercial software. Indeed, for large-scale FE 3D simulations, the efficient exploitation of HPC resources becomes a must for providing a reasonable time-to-solution.…”

mentioning

confidence: 99%

Simulation of High Temperature Superconductors and experimental validation

Olm

Badia

Martı́n

2019

Computer Physics Communications

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In this work, we present a parallel, fully-distributed finite element numerical framework to simulate the low-frequency electromagnetic response of superconducting devices, which allows to efficiently exploit HPC platforms. We select the so-called H-formulation, which uses the magnetic field as a state variable. Nédélec elements (of arbitrary order) are required for an accurate approximation of the H-formulation for modelling electromagnetic fields along interfaces between regions with high contrast medium properties. An h-adaptive mesh refinement technique customized for Nédélec elements leads to a structured fine mesh in areas of interest whereas a smart coarsening is obtained in other regions. The composition of a tailored, robust, parallel nonlinear solver completes the exposition of the developed tools to tackle the problem. First, a comparison against experimental data is performed to show the availability of the finite element approximation to model the physical phenomena. Then, a selected state-of-the-art 3D benchmark is reproduced, focusing on the parallel performance of the algorithms.

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2D and 3D numerical modeling of experimental magnetization cycles in disks and spheres

Cited by 18 publications

References 22 publications

Demagnetization of Cubic Gd-Ba-Cu-O Bulk Superconductor by Crossed-Fields: Measurements and Three-Dimensional Modeling

Demagnetization of Cubic Gd-Ba-Cu-O Bulk Superconductor by Crossed-Fields: Measurements and Three-Dimensional Modeling

Superconducting and hybrid systems for magnetic field shielding

Simulation of High Temperature Superconductors and experimental validation

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