Numerical Simulation of Fluid Flow and Heat Transfer at Supercritical Pressures of Water Coolant for a Wire-Wrapped Rod Bundle

In this work, to assess the efficiency of the ANSYS CFX 14.0 code and obtain fluid flow properties, one heat transfer experiment using water as a coolant at supercritical pressures was selected: a 2 × 2 rod bundle with wire spacers along its length. A 3D CFD study of fluid flow and heat transfer at supercritical pressures was conducted for the geometry of the rod bundle, with the key parameter being the temperature of the inner wall of the fuel rod simulator. The influence of turbulence models SST, k–ω, and BSL, as well as various types of computational mesh to ensure the reliability of the assumed wall temperature, was investigated. After the study, the CFD model data was verified against experimental data. It was found that the CFD model was able to qualitatively describe the temperatures of the inner surfaces of the rods as reported in the experiments.