Design of a single-phase PTS numerical experiment for a reference Direct Numerical Simulation

The aim of this work is to design a numerical experiment aimed to generate a high quality reference DNS database for a simplified PTS scenario. This takes into account the turbulent mixing in the downcomer and the evolution of the temperature distribution for both structures and fluid during a single-phase flow PTS scenario. In spite of simplifications, such a DNS analysis represents a very demanding application. A priori, it should be demonstrated that all the relevant turbulent scales will be fully resolved, which requires a huge computational power. A wide range of Reynolds Averaged Navier-Stokes (RANS) calculations are performed in order to determine a realistic PTS computational domain. Furthermore, the resulting numerical experiment is optimized in terms of geometry, boundary conditions, and physical properties.