Heat transfer characteristics of liquid LBE in narrow rectangular channel

<bold>Background</bold>Narrow rectangular channels can be widely used in the field of reactor engineering because of its compact structure and good heat transfer ability. And lead-bismuth eutectic (LBE)is a candidate coolant for the fourth generation liquid metal reactor.<bold>Purpose</bold>This study aims to effectively utilize the Reynolds Average Navier-Stokes Equation (RANS) model for numerical simulation of heat transfer characteristics in liquid metal-cooled rectangular narrow channels and propose a recommended model combination.<bold>Methods</bold>The geometric model of a narrow rectangular channel was established, and Computational Fluid Dynamics (CFD) code Fluent was employed to calculate the Nusselt number under different turbulence and <italic>Pr</italic>_t models. The numerical simulation results was compared with the empirical relationship for liquid metal heat transfer in narrow rectangular channels, through which the most suitable model combination for calculating liquid metal heat transfer characteristics was determined. Finally, the boundary layer structural characteristics of several models were comparatively analyzed.<bold>Results</bold>The results show that the error between the calculated Nusselt number and the empirical relationship is less than 10% by choosing the Standard <italic>k-ω</italic> or Realizable <italic>k-ε</italic> turbulence model and the <italic>Pr</italic>_t model proposed by Cheng&amp;Tak. In addition, as the increase of <italic>Pr</italic>_t, the logarithmic region <italic>T</italic>⁺ in the temperature boundary layer decreases, and the thickness of the temperature boundary layer decreases.<bold>Conclusions</bold>The results of this study have important reference value for accurately simulating the turbulent heat transfer of liquid metal in narrow rectangular channels.