Characterization of flow in sub-scale cable-in-conduit conductors

The authors measured the pressure drop of supercritical helium and He II counterflow heat transport in subscale cable-in-conduit conductors (CICCs) at a variety of different temperatures. These measurements were made on various conductors with different flow areas, void fractions, and strand diameters. Classical friction factor analysis was used to correlate the pressure drop results. The results of this analysis revealed systematic variations in the friction factor which appear to be dependent on the temperature of the helium. In a separate experiment heat transport in He II contained in the CICCs was analyzed in terms of the Gorter-Mellink relationship to obtain an independent determination of the flow cross-sectional area. These cross-sectional areas were used to reanalyze previously reported pressure drop data on the same conductors. Use of He II counterflow measurements as a general method to characterize the hydraulics of these conductors is discussed.<>