Computational fluid dynamics (CFD) codes are widely used to investigate the thermal hydraulics of revolutionary reactor concepts in the last decade. Most CFD codes, including ANSYS CFX, solve Navier-Stokes equations by Reynolds averaging approach, which use turbulence models and wall functions. These turbulence models and wall function are validated against experimental data under subcritical pressures. However, the applicability of them to supercritical water heat transfer has to be examined. The objective of the present study is to evaluate the performance of the turbulence models of CFX in predicting supercritical heat transfer under non-buoyancy influence and strong buoyancy influence. The calculation results have been compared with two independent validation experimental data. The results indicate the need to improve a turbulence model to take into account the buoyancy effect and property variations on the turbulence for thermal-hydraulic calculations of the supercritical water when the buoyancy influence is strong.

This content is only available via PDF.
You do not currently have access to this content.