Triangular rod bundle simulations of a CFD κ-ϵ-κθ-ϵθ heat transfer turbulence model for heavy liquid metals

• We model the heat transfer in heavy liquid metals with a new κ-ϵ-κθ-ϵθ turbulence model.
• We validate the κ-ϵ-κθ-ϵθ turbulence model with DNS and experimental correlations in plane and cylindrical geometry.
• We compare the results for triangular rod bundle simulations with experimental heat transfer correlations.
• We compare the results for different pitch-to-diameter ratios.
• We compare the results with other heat transfer turbulence models.

Heavy liquid metals are often considered as coolant fluids for fast nuclear reactors because of their physical and neutronic properties. Nevertheless, these fluids are not well known as ordinary fluids, such as air or water, and the use of reliable numerical tools for the simulation of turbulent heat transfer inside reactor cores refrigerated with liquid metals is still an open issue. In the present work we propose the use of a κ-ϵ-κθ-ϵθ turbulence model to improve the prediction of turbulent heat transfer for liquid metal flows in triangular rod bundle geometry with different pitch-to-diameter ratios and different Peclet numbers. Nusselt number comparisons between experimental correlations and different heat turbulence models are reported for many test cases.