Prediction of Void Fraction in Sub-Cooled Flow Boiling at High Pressure Using Distribution Parameter Correlations

Abstract

In this work, the void fraction based on the Zuber and Findlay model is evaluated at onset of nucleate boiling (ONB) using the Delhaye et al expression of true quality and onset of significant void (OSV) using the Manon expression of true quality. The distribution parameter correlations of Hancox–Nicoll, Nabizadeh, DIX and a data fitting distribution parameter correlation from the DEBORA experiment which was extended for light water were considered. The numerical modeling of the forced convective subcooled boiling water was done at the pressures and mass fluxes of 12.5 MPa and 2800 kg m\(^{-2}\) s\(^{-1}\), 15.7 MPa and 3600 kg m\(^{-2}\) s\(^{-1}\), and 16.2 MPa and 3836 kg m\(^{-2}\) s\(^{-1}\), respectively, corresponding to the operating parameters of pressurized water reactors (PWRs). The result of the calculation indicates that the Dix and Nabizadeh distribution parameters highly deviated from the DEBORA fitted data prediction at the pressure and mass flux range used, and both distribution parameters almost overlapped in their prediction of void fraction at 16.2 MPa. Within the pressure and mass flux range used for this calculation, the Hancox and Nicoll distribution parameter predicted void fraction were below the DEBORA fitted data prediction and deviation increased as pressure and mass flux decreased.