Calculations of pressure drop and mass flow distribution in the toroidal field model coil of the ITER project

In preparation of the ITER FEAT project, a superconducting toroidal field m odel coil (TFMC) including 10 parallel pancakes of between 72.2 and 82.0 m long cable-in-conduit conductor (CICC) has been built and has to be tested at FZK. A series of preliminary tests were performed at room temperature an d in nitrogen at both CEA-Cadarache and Ansaldo. The tests aimed to assess the thermohydraulics of this coil and specifically to address the pressure drop and the friction factor of the dual channel CICC in a range of Reynold s numbers relevant to the TFMC. These measurements are compared with the pr edictions which include a hydraulic description of the joint region whose c ontribution to the total pressure drop is non-negligible. The mass flow dis tribution between the bundle region and the central channel will be calcula ted for the cable as well as for the joint region. Measurements on the cent ral solenoid model coil (first layer of inner module and insert coil) in no rmal operating conditions with supercritical helium are presented. They are in good agreement with the calculations performed from the previously vali dated correlations. A description of the mass flow imbalance between the TF MC pancakes at low temperatures in helium is done. The major influence of t he central spiral is confirmed, since two types of spirals have been includ ed in the TFMC pancakes. This distribution varies as a function of the tota l mass flow of the analysed hydraulic circuits (TF and CS) of ITER-FEAT. (C ) 2001 Elsevier Science Ltd. Al rights reserved.