Numerical model using an implicit finite difference algorithm for stability simulation of a cable-in-conduit superconductor

A new numerical model and calculation method for stability simulation of a cable-in-conduit conductor (CICC) has been developed. In this model, the governing equations are a one-dimensional fluid dynamics equation and heat conduction equations for strands and a conduit. Precise modelling of transient heat transfer from the strands to the coolant is the key to accurate simulation of stability. Modelling of the transient heat transfer coefficient is carried out more accurately than the conventional model by taking into account the variation in the heat flux and the temperature around the strands. The governing equations are made discrete by an implicit time-dependent finite different scheme to avoid any limitation from the CFL ( Courant-Friedrichs-Lewy) condition. The finite different equation for the fluid is linearized according to a certain procedure used by Beam and Warming, resulting in a tridiagonal system. Therefore, no iteration is necessary to solve the fluid dynamics equation, in spite of the use of the implicit scheme. As a result, a large amount of CPU time could be saved. The simulated and experimental results of stability for a small CICC was compared for verification of the code. The results were in good agreement, resulting in a completion of the verification of the code. (C) 1996 Elsevier Science Limited