Enhancing Thermal-Hydraulic Modelling in Dual Fluid Reactor Demonstrator: The Impact of Variable Turbulent Prandtl Number January 1, 2025 H Elgendy S Kubacki K Czerski Computational Fluid Dynamics (Cfd) Dual Fluid Reactor (Dfr) Kays Correlation Thermal-Hydraulic Modelling Variable Turbulent Prandtl Number