A Numerical Study of Turbulent Upward Flow of Super Critical Water in a 2 × 2 Rod Bundle With Nonuniform Heating

Abstract

This work is part of a benchmarking exercise organized by an IAEA in supercritical water-cooled reactor (SCWR) thermal-hydraulics aimed at improving the understanding and prediction accuracy of the thermal-hydraulic phenomena relevant to SCWRs. An experiment carried out using a 2 × 2 SCWR bundle at University of Wisconsin-Madison was modeled using an open-source computational fluid dynamics (CFD) code—Code_Saturne. The k–ω shear stress transport (SST) model was used to account for the buoyancy-aided turbulent flow in the fuel channel. Significant heat transfer deterioration (HTD) was observed in the boundary layer, which is commonly expected to occur in buoyancy-aided flows. For comparison, simulations were also conducted using ansysfluent with similar model setups.