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Superconducting Magnet Systems Chapter | 5 159

rameters. The thermal–hydraulic properties of the solids (structures and SC
cables) are described as functions of temperature. The code utilises a com-
mon database of coolants in a tabular format suitable for describing any
coolant. Kinetic and thermodynamic properties of a coolant are presented
in terms of enthalpy and pressure. The database is generated using data
derived from the HEPAK [27] and REFPROP [28] computer packages. A
set of intrinsic functions provides customisation and calculation of coolant
characteristics.

A.5.1.2 Validation of Vincenta/Venecia Models for Thermal–
Hydraulic Analysis of SC Magnets and Their Cryogenic Circuits
The Vincenta/Venecia codes have been employed for the past 20 years for a
full-scale modelling of the thermal–hydraulic behaviour of the ITER magnets
and their cryogenic circuits. These codes’ capabilities were used to obtain a set
of consistent thermal–hydraulic models for all the ITER magnets. Every mag-
net model comprises a few thousand basic elements described by 1D and 2D
models. Millions of thermodynamic parameters are calculated simultaneously
for those elements.
Simulations are used to validate and optimise the design solutions, which
makes their reliability a matter of critical importance. When applied to relatively
simple problems, Vincenta/Venecia simulations demonstrated consistency with
experimental results. Mismatches between theory and experiment were due to
the inaccuracy of input data on heat load distribution and the inevitable use of
some semi-empirical coefficients. However, the question of how reliable the re-
sults obtained with complex numerical models are remained open for quite a
while, and it was extremely important to check detailed data from a physical
experiment on a large SC facility against a complex numerical model of the
same experiment, similar to that used for a thermal–hydraulic analysis of ITER
magnets operation.
The CSMC experiments in Japan in 2000 provided voluminous data for the
validation of the Vincenta/Venecia models. CSMC had been manufactured as
part of ITER activities and intended to investigate the performance of super-
conducting cables for ITER. A brief summary of CSMC features is presented in
Fig. 5.19 and Table 5.8.
The CSMC is configured as a helicoid coil consisting of two modules with
layered two-in-hand windings. Each layer is wound in parallel with two (A and
B) CIC SCs. Each CIC conductor has two parallel flow channels, namely, the
central channel and the bundle channel. The inner and the outer CSMC modules
have 10 and 8 layers, respectively.
The Vincenta/Venecia CSMC model was developed in 2001 to simulate coil
behaviour in a series of trapezoidal current pulses with increasing amplitude
fed into the coil. The current pulses generated heavily pulsed heat in the CSMC