Investigation of pressure loss and velocity distribution in fuel assemblies with wire-wrapped rods by using RANS and LES with wall functions

Hexagonal assemblies of wire wrapped fuel rods were analyzed experimentally at Texas A&M University. CFD analysis with LES and RANS (SST k-ω) a 61-pins experiment have already been published by using wall resolved meshing. These results are compared in this study to calculations functions, more precisely (k-ε) LES. The presented comparison will be used as reference result the design based models for reactor core sodium cooled fast breeder reactors, since next generation developed CEA use functions. It is shown that velocity profiles turbulence reasonable accordance among each other. However, functions overestimates pressure loss rod bundles.