Numerical Analysis on Heat Transfer-Characteristics of Supercritical Pressure Water in a Heated Tube Based on Three Dimensional Two-Fluid Model

In Japan Atomic Energy Agency (JAEA), the three-dimensional two-fluid model analysis code considering the supercritical pressure water based on ACE-3D (Advanced Code for Evaluation of 3-Dimensional two-phase flow) has been developed to establish the thermal-hydraulics design by numerical analytical approach for the Super Critical Water Reactor (SCWR). In this paper, in order to evaluate the prediction accuracy of ACE-3D for the heat transfer-characteristics at the pseudo critical point, a numerical analysis of the supercritical water using ACE-3D based on the three dimensional two-fluid model has been conducted for simulating the experiments in a heated tube with both upward and downward flow. For the turbulence model in this analysis, both the standard k-ε model and the low-Reynolds number type k-ε model which uses the Launder-Sharma model were examined to investigate the influence of the turbulence model on the heat transfer-characteristics near the heated wall near the pseudo critical point. As a result, it was found that the numerical results of wall temperature using the low-Reynolds number k-ε model for upward flow in a heated tube were in good agreement with experimental data compared with that of using the standard k-ε model.