Numerical simulation of moving boundary problems in superconducting magnets

摘要

In the design and operation of superconducting magnets, quench is always an important consideration. Superconductors are designed to operate at very high current density, for example, 10~(10) A/m~2, so when an external disturbance is strong enough, the superconductor will go from the superconducting state (zero resistance) to the normal state (resistive conductor), which constitutes a quench. The dangers of overheating if a magnet quenches are obvious. A high order finite difference scheme is introduced to deal with thermo-hydraulic quench simulation in superconducting magnets, specifically in the case of cable-in-conduit conductors (CICC). Liquid helium flow in CICC is governed by the unsteady convection-diffusion equations, in the regime of low Mach number and high Reynolds number flow. The numerical simulations of quench propagation are key to proper magnet protection design. In fact, the main goal of our research is to seek an algorithm exhibiting both high accuracy and efficiency in solving this particular problem. A special high order scheme, the Dispersion-Relation-Preserving (DRP) method, is applied to the quench simulation problem. Some effort is placed on the improvement of present work by DRP scheme, and benchmarking results are given to compare with results obtained by other methods as well as experimental data.