A Comparative Analysis of CFD Approaches to Model Wire-Wrapped Fuel Bundle and Experimental Validation

Abstract A wire-wrapped fuel bundle of 19 rods using Lead-Bismuth Eutectic (LBE) as a coolant was chosen for this CFD study and the predictions are compared to the NACIE-UP benchmark experimental data. The k-ω SST turbulence model is used to investigate the heat transfer of the LBE together with the adoption of a constant turbulent Prandtl number of 1.5. The thermo-dynamic properties of the LBE are modelled as temperature-dependent polynomials. Three different approaches have been adopted in this work to model the FPS, namely, Bare, Detailed, and the Porous Rod Bundle model. A model-to-model comparison is performed to understand the benefits, limitations, and accuracy of using porous models for representing wrapped wire. Furthermore, the integration of NACIE-UP benchmark experimental data into the comparative analysis adds an additional layer to validate the modelling approach.