Development of an Integrated Thermo-Mechanical Simulation Environment for Quench Analyses in HTS Cables for Fusion

In the last years several experimental campaigns have been carried out to assess the performance of High Temperature Superconducting (HTS) cables for nuclear fusion applications. In such experiments it has been often observed that cable performance in terms of critical current <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$(I_{c})$</tex-math></inline-formula> degrade, mainly after quenches. The nature of the degradation is not completely assessed, but secondary strains given by temperature increase are considered to be its responsible. To confirm such statement it is necessary to develop a tool capable of reproducing the quench effects both from the thermal and from the mechanical points of view, aiming at retrieving the induced strain field in the conductor itself. The aim of this work is presenting the development of a simulation environment which embeds both the required features mentioned above. The thermal-hydraulic (TH) aspects of the quench are analysed here with the H4C code, developed at Politecnico di Torino and spreadly validated against several quench campaigns in SULTAN. The output of the H4C code represents an optimum set of inputs for a detailed mechanical model of the cable. For this reason a python API has been developed making the H4C code communicate with ANSYS, used to compute, on the base of the temperature profiles in input, the consequent strain field. The simulation environment developed has been applied to a slotted core HTS conductor to check its functionalities, showing good agreement with the physical expectations.