Development of a Drift-flux Model for Heavy Liquid Metal/Gas Flow

Abstract

The gas lift pump concept based on the bubbling of an inert gas into the primary reactor coolant to enhance natural circulation is currently considered in a number of PbBi-cooled reactor concepts. Thus, the analysis of available void fraction data and the development of two-phase heavy liquid metal/gas flow calculational models have become an important issue in the study of advanced nuclear reactor systems. In the absence of the detailed two-phase flow information needed to develop a flow regime map and the associated interfacial relations, drift-flux models have often been used in the thermal-hydraulic analysis of nuclear and other systems. Accordingly, we consider, in the current paper, the analysis of five sets of experimental data with different geometries, working fluids, flow rates and void fraction ranges, with a view to obtaining a best fit to the data in the form of a drift-flux model. The results of the analysis show that, for systems with flowing fluid, it is possible to represent the heavy liquid metal void fraction data in the form of a drift-flux correlation with a residual error of as low as 0.016, thus offering an improvement over existing void correlations.

Development of drift-flux correlations for vertical forward bubble column-type gas-liquid lead-bismuth two-phase flow

“…As for gas-liquid metal two-phase flow, Mikityuk et al (2005) analyzed five sets of experimental data with different geometries, working fluids, flow rates, and void fraction ranges and compared four types of correlations for pooltype (average superficial liquid velocity is zero) and looptype channels. The recommended correlations are given by Equation 12.…”

Evaluation of Pb-Bi-Water Direct Contact Boiling Flow in a Vertical Circular Channel using Drift-Flux Model

“…Appropriate correlations for the drift velocity and the drag coefficient between nitrogen gas and Pb-Bi phase were based on the drift flux correlation of measured pool void fraction 7) . And another correlation for drift-flux model between nitrogen gas and liquid metal for measured loop-type experiment void fraction 8) .…”