AN EXPERIMENTAL INVESTIGATION OF TWO-PHASE FLOW INTERACTIONS IN HORIZONTAL ROD BUNDLE GEOMETRIES

An experimental study to investigate two-phase flow redistribution in horizontal subchannel flow, in the absence of a transverse pressure gradient, is presented. An air-water loop with a two subchannel horizontal test section is used. Redistribution data includes the axial variation of gas and liquid flow rates as well as void fraction in "both subchannels. The observed redistribution data are found to exhibit an asymptotic behaviour approaching equilibrium distributions beyond which no further exchanges are observed. The equilibrium distributions are found to be mass flux and quality dependent. The mechanisms involved are modelled using a simple diffusion model from which a dimensionless redistribution parameter is defined. Based on the present data, the redistribution parameter increases with decreasing mass flux and increasing quality, however, the mass flux effect seems to be more pronounced.