SIMULATION OF TALL-3D EXPERIMENTAL FACILITY WITH A MULTISCALE AND MULTIPHYSICS COMPUTATIONAL PLATFORM

This work details the development of a computational platform in joint collaboration between the Italian National Agency for New Technologies, Energy and Sustainable Economic Development (enea) and the University of Bologna (unibo). The platform is based on the open-source SALOME software that integrates the CATHARE system code for nuclear safety, FEMUS and OpenFOAM CFD codes in a unique framework, with efficient methods for data exchange. The computational platform has been used to simulate complex multiscale and multiphysics systems, such as the tall-3d facility, with a defective boundary condition approach on overlapping domains. The tall-3d experimental facility has been realized with the purpose of providing reference results to be used for both standalone and coupled System Thermal-Hydraulic (STH) and Computational Fluid Dynamic (CFD) code validation. The transient phenomenon of unprotected loss of lead-bismuth eutectic (LBE) flow that has been experimentally simulated at tall-3d is here studied. The system code is used to simulate the tall-3d apparatus while the CFD code is used to get a better insight into the fluid streaming occurring in the main tank component and improve the system code predictions. A flow transition from forced to natural convection is used to validate the codes and the platform ability to reproduce the experimental data.