Electromagnetic-thermal coupling simulation in high temperature superconducting bulk by peridynamic differential operator

Abstract

The high temperature superconducting (HTS) bulk can operate in the liquid nitrogen temperature. A useful model describing superconductivity for engineering applications links electric field and current density, namely as E-J power law. Since the exponent of the E-J power law is usually set as 20∼50, the distribution of current density changes dramatically between the penetrated and unpenetrated regions, which brings a challenge to the numerical accuracy and convergence of the calculation. Furthermore, in order to simulate the heat transfer behavior between HTS bulk and its ambient environment during operation, the nonlinear flux boundary condition of temperature is employed. The peridynamic differential operator (PDDO) is a powerful tool to solve the mathematical model with PDEs. Utilizing the theory of the PDDO, the spatial partial derivative in the PDEs is converted into a corresponding non-local form. To verify our model, a comparison between the numerical results solved by the PDDO and finite element method is carried out. Finally, the effects of the global and local non-uniformity of critical current and thermal perturbation on the electromagnetic and thermal behaviors of the HTS bulk in the multi-pulsed field magnetization process are simulated.