A Pressure Drop Model for Helium Flow in CIC Conductors Based on Porous Media Analogy

Pressure drop of cable-in-conduit conductors (CICCs) cooled by a flow of liquid or supercritical helium is one of the key parameters for the design of large superconducting magnet systems, which determines the heat removal capability and the thermal stability. In this article, an analytical model for predicting the pressure drop in CICCs is developed based on an analogy to porous media with the equivalent geometry configuration. This new prediction model indicates that the pressure drop in CICCs is affected by the geometry parameters of cable and the physical properties of the liquid helium, such as void fraction, tortuosity, pore-throat ratio, hydraulic diameter, density, and viscosity of the liquid helium. To verify the validity of the pressure drop model proposed in this article, the predictions are compared with the experimental data, the results show that the predictions are in good agreement with the experimental data. Then, an analytical expression for predicting the friction factor is derived, the obtained expression is in good agreement with experimental data and is superior to the Katheder correlation at large Reynolds number. In addition, the effects of the major geometric parameters on pressure drop are analyzed, the results explain why the Katheder correlation can be used to predict the pressure drop of CICCs.