Turbulent Flow Simulations Of Wire-wrapped Fuel Pin Bundle Of Sodium Cooled Fast Reactor In Lattice-Boltzmann Framework

Lattice-Boltzmann method (LBM) simulations were performed for sodium cooled fast breeder type nuclear reactors with helical spacer wires in order to validate the Smagorinsky Large Eddy Simulations (LES) and Very Large Eddy Simulations (VLES) turbulence models implemented in lattice-Boltzmann framework. An open source lattice-Boltzmann solver Palabos code is used for the simulations. Palabos already contains Smagorinsky-Lilly LES turbulence model. Thus, in this work, the code is enhanced by the addition of turbulence model VLES. The simulations are handled for hexagonal fuel rod bundle for seven rods with two-helical-pitch length geometry. For each turbulence model study, post-processed turbulence quantities such as velocity profiles and Reynolds stresses are compared. Additionally, the friction factor obtained from LES and VLES are compared with the experimental data. The comparisons show that LBM simulations are in good agreement with experimental correlations. Validation of written code in C++ programming language is encouraging for the simulation of more complex geometries for the nuclear reactor fuel bundle system in the future.