Computational assessment of thermo-hydraulic performance of Al₂O₃-water nanofluid in hexagonal rod-bundles subchannel

This study investigated alumina nanofluid's thermo-hydraulic performance as a coolant in the subchannel geometry of a hexagonal rod-bundle reactor core using the computational fluid dynamics (CFD) tools. This study analyzed the critical thermo-hydraulic performance-the heat transfer enhancement for an permissible increased pressure drop limit while considering the variation in the volume of nanoparticles concentrations, consistent with the previous related studies. The simulation model was developed for single-phase, forced, and turbulent flow conditions with a homogeneous mixture of species. The simulation results compared with the relevant standard correlations for the inlet Reynold number range of 20,000 to 80,000. Our study exhibited that heat transfer can be improved significantly with the addition of nano-size particles. This rise in heat transfer decreased the fuel clad surface temperature, improving the reactor fuel-clad temperature safety margin. However, the pressure drop also increased considerably, which needed to be within the permissible limit. Therefore, a trade-off between the heat transfer enhancement and drawback of the increased pressure drop within the reactor design limit is recommended.