TY - JOUR
T1 - Fast and efficient critical state modelling of field-cooled bulk high-temperature superconductors using a backward computation method
AU - Zhang, Kai
AU - Ainslie, Mark
AU - Calvi, Marco
AU - Hellmann, Sebastian
AU - Kinjo, Ryota
AU - Schmidt, Thomas
N1 - Funding Information:
Original content from this work may be used under the terms of the . Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Engineering and Physical Sciences Research Council (EPSRC) Early Career Fellowship EP/P020313/1 European Union’s Horizon2020 research and innovation program 777431 yes � 2020 The Author(s). Published by IOP Publishing Ltd Creative Commons Attribution 4.0 license
Publisher Copyright:
© 2020 The Author(s). Published by IOP Publishing Ltd.
PY - 2020/10/7
Y1 - 2020/10/7
N2 - A backward computation method has been developed to accelerate modelling of the critical state magnetization current in a staggered-array bulk high-temperature superconducting (HTS) undulator. The key concept is as follows: (i) a large magnetization current is first generated on the surface of the HTS bulks after rapid field-cooling (FC) magnetization; (ii) the magnetization current then relaxes inwards step-by-step obeying the critical state model; (iii) after tens of backward iterations the magnetization current reaches a steady state. The simulation results show excellent agreement with the H-formulation method for both the electromagnetic and electromagnetic-mechanical coupled analyses, but with significantly faster computation speed. The simulation results using the backward computation method are further validated by the recent experimental results of a five-period Gd-Ba-Cu-O (GdBCO) bulk undulator. Solving the finite element analysis (FEA) model with 1.8 million degrees of freedom (DOFs), the backward computation method takes less than 1.4 h, an order of magnitude or higher faster than other state-of-the-art numerical methods. Finally, the models are used to investigate the influence of the mechanical stress on the distribution of the critical state magnetization current and the undulator field along the central axis.
AB - A backward computation method has been developed to accelerate modelling of the critical state magnetization current in a staggered-array bulk high-temperature superconducting (HTS) undulator. The key concept is as follows: (i) a large magnetization current is first generated on the surface of the HTS bulks after rapid field-cooling (FC) magnetization; (ii) the magnetization current then relaxes inwards step-by-step obeying the critical state model; (iii) after tens of backward iterations the magnetization current reaches a steady state. The simulation results show excellent agreement with the H-formulation method for both the electromagnetic and electromagnetic-mechanical coupled analyses, but with significantly faster computation speed. The simulation results using the backward computation method are further validated by the recent experimental results of a five-period Gd-Ba-Cu-O (GdBCO) bulk undulator. Solving the finite element analysis (FEA) model with 1.8 million degrees of freedom (DOFs), the backward computation method takes less than 1.4 h, an order of magnitude or higher faster than other state-of-the-art numerical methods. Finally, the models are used to investigate the influence of the mechanical stress on the distribution of the critical state magnetization current and the undulator field along the central axis.
UR - http://www.scopus.com/inward/record.url?scp=85094327145&partnerID=8YFLogxK
U2 - 10.1088/1361-6668/abb78a
DO - 10.1088/1361-6668/abb78a
M3 - Article
AN - SCOPUS:85094327145
SN - 0953-2048
VL - 33
JO - Superconductor Science and Technology
JF - Superconductor Science and Technology
IS - 11
M1 - 114007
ER -