Investigation of super-critical water-based nanofluid with different nanoparticles (shapes and types) used in the rectangular corrugated tube of reactors

In this paper, an optimized rectangular corrugated tube is used for the super-critical water reactor (SCWR) cooling, numerically. Al₂O₃, CuO, Fe₃O₄ and TiO₂ nanoparticles in different shapes (spherical, brick, platelet and cylindrical) are considered as additives to SCW for cooling purposes, and it is tried to introduce the most suitable cases from the maximum heat transfer view point. Piecewise temperature-dependent properties are considered for the SCW and different correlations such as Brinkman and Pak equations were examined for nanofluid properties. The governing equation are solved based on control volume method (CVM) software, where the SCW properties are introduced to it by a user defined function (UDF). As the main outcome, Pak and Cho correlation had the best fitted curves with other presented functions. Also, the corrugated tube filled by spherical alumina-SCW had the best performance for SCWR cooling.