Mithrandir+: a two-channel model for thermal-hydraulic analysis of cable-in-conduit super-conductors cooled with helium I or II

Abstract Mithrandir [1] – a 1-D code for the analysis of thermal-hydraulic transients in cable-in-conduit super-conductors (CICC) with cooling channel – has been extended to helium II by including Gorter-Mellink heat transport. The code treats the general case of different thermodynamic properties and flow velocities for the helium in the cable bundle region and that in the cooling channel, which are coupled to conductor and jacket at different temperatures. A detailed validation of the code against a thermal-hydraulic experiment in helium II is presented, showing good agreement, and code convergence is demonstrated numerically. We present results of simulations of the QUench Initiation and Propagation Study (QUIPS) experiment, concentrating mostly on the initial phase of the quench. We show that the simulation is at least qualitatively in agreement with experimental data.