<p>Since 2000, amid growing concerns over energy conservation and emission reduction, liquid-fueled molten salt reactors (LF-MSR) have regained considerable attention. However, there is still a lack of applicable correlations for the developing turbulent flow and heat transfer of molten salt under the coupled effects of internal heat generation and inward wall heat flux. To address this gap, numerical simulations are performed using ANSYS Fluent with the Reynolds Stress-BSL turbulence model to systematically investigate the thermal–hydraulic performance and entropy generation characteristics. Parametric analysis reveals that the friction factor decreases with increasing wall heat flux, Reynolds number, and inlet temperature and with decreasing tube diameter, while the standalone effect of internal heat generation rate is negligible. The equivalent Nusselt number increases with increasing internal heat generation rate, Reynolds number, inlet temperature, and tube diameter and decreasing wall heat flux; the performance index shows the same trend while decreasing with increasing tube diameter. The heat transfer irreversibility dominates the total irreversibility; it increases with internal heat generation rate, wall heat flux, and tube diameter, but decreases with Reynolds number and inlet temperature. The exergy efficiency, which depends on the wall heat flux, decreases with increasing wall heat flux. Finally, new correlations for the equivalent Nusselt number and friction factor are proposed, with a maximum relative deviation of 14.8% from experimental data for the Nusselt number correlation and 8.7% from numerical data for the friction factor correlation, respectively. The present findings can be directly applied to the preliminary design of liquid-fueled molten salt reactors.</p>