Comparative thermal-hydraulic analysis of parallel and counter flow configurations in a dual fluid reactor mini demonstrator

This article explores the comparative thermal–hydraulic behavior of parallel and counter flow configurations within the mini demonstrator (MD) of the Dual Fluid Reactor (DFR). Utilizing detailed computational fluid dynamics (CFD) simulations, we analyze the heat transfer characteristics, velocity distribution, and swirling effects for both configurations. Given the uniquely low Prandtl number of the liquid lead used in the MD and DFR, the CFD modeling in this study incorporates a variable turbulent Prandtl number. This approach has been validated in our previously published work. The results demonstrate that the counter flow configuration yields higher heat transfer efficiency and more uniform flow velocity, while reducing swirling and mechanical stresses. These findings provide valuable insights for optimizing the DFR’s design, improving safety, and enhancing operational performance.