Abstract
The fundamental two-phase flow characteristics of slush nitrogen in a pipe are numerically investigated to develop effective cooling performance for long-distance superconducting cables. First, the governing equations of two-phase slush nitrogen flow based on the unsteady thermal non-equilibrium two-fluid model are constructed and several flow characteristics are numerically calculated taking into account the effects of slush volume fraction, thermodynamic behavior of slush, and duct shape. Furthermore, the numerical results are compared with previous experimental results on pressure loss measurement and visualization measurement in two-phase slush nitrogen flow along the longitudinal direction of the pipe. According to this research, it is found that reducing the pressure loss using a two-phase slush flow is possible under the high Reynolds number condition and by applying the appropriate volume fraction of slush particles. The optimized thermal flow conditions for cryogenic two-phase slush nitrogen with practical use of latent heat for slush melting are predicted for the development of a new type of superconducting cooling system.
