Heat transfer characteristics of the supercritical helium in a cable-in-conduit conductor

To study the thermal stability of a forced-cooled superconducting coil with a cable-in-conduit conductor (CICC), it is important to measure the steady-state heat transfer characteristics of the supercritical helium in the narrow channel like a CICC at various conditions. The measured heat transfer coefficient is compared with one calculated by the Giarratano correlation and other studies. The results obtained show that measured values for turbulent flow scatter widely and the values for laminar flow are 1.5-1.8 times larger than those calculated from Nu=4.36. The stability of a CICC is discussed with the relation between the Stekly's stability limit and the measured heat transfer coefficient.<
>