Simulation by Finite Difference Numerical Method of ${\rm Nb}_{3}{\rm Sn}$ Strand Under Bending Strain
Simulation by Finite Difference Numerical Method of ${\rm Nb}_{3}{\rm Sn}$ Strand Under Bending Strain
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DOI：
10.1109/tasc.2009.2019098
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发表时间：
2009-06
影响因子：
1.8
通讯作者：
C. Fiamozzi Zignani;V. Corato;A. della Corte;A. Di Zenobio;G. Messina;L. Muzzi
中科院分区：
文献类型：
--
作者：
C. Fiamozzi Zignani;V. Corato;A. della Corte;A. Di Zenobio;G. Messina;L. Muzzi
在Mathworks环境下，用有限差分法求解隐式扩散方程，模拟了纯弯曲应变下Nb3Sn钢绞线中的电流分布。临界电流与弯曲、温度和磁场的关系由改进的偏转标度定律模拟，并用于超导体上电场的幂函数关系。线束被离散成表示嵌入在稳定矩阵中的扭丝组的单元，并且分布式恒定电路模型被应用于丝束之间的电流传递。通过与不同简化情况下的解析解的比较，初步验证了该程序的有效性，每个解析解对应一个适当的边界条件。横向矩阵电阻率和扭距是将数值计算结果与实验测得的临界电流进行匹配的关键因素。
We report on the simulation of the current distribution in Nb3Sn strand subjected to pure bending strain, obtained by resolving the implicit diffusion equations with finite difference algorithm in Mathworks environment. The critical current dependence on bending, temperature, and magnetic field is modeled by the Improved Deviatoric Scaling Law and is used in the power law electric field dependence across the superconductor. The strand is discretized in elements representing groups of twisted filaments embedded in the stabilization matrix and a distributed constant circuit model is applied for current transfer among filament bundles. The code is preliminarily validated by comparison with analytical solutions for different simplified situations, each one corresponding to a proper boundary condition. Transverse matrix resistivity and twist-pitch values are crucial elements for matching numerical results with experimentally measured critical currents.