Numerical Investigation of Changes in Heat Transfer Coefficient of Water-Aluminum Oxide Nanofluid Cooling in Nuclear Reactors

In this study, the free and forced heat transfer coefficient of the water-based aluminum oxide nanofluid used as a coolant around a fuel rod is numerically investigated in the ANSYS Fluent program. The heat flow generated along the length of the rod is not uniform and resembles the real reactor fuel rod. Flow parameters, such as fluid mass and wall temperature, are calculated using numerical methods. Heat transfer coefficients can be obtained by estimating these parameters and obtaining the heat flux profile as well as the properties of the nanofluid. In this respect, this study provides a novel analysis of the interplay between nanofluid properties and flow dynamics, offering insights crucial to enhancing reactor cooling performance. The results show that the average heat transfer coefficient varies depending on the nanofluid concentration. However, the tendency of heat transfer and Nusselt coefficient changes decreases in the slow flow region and increases in the turbulent flow. In general, heat transfer will increase when nanofluid is used as a coolant around the fuel rods.