Development of a dimensionless flooding correlation based on experimental study on air-water countercurrent flow limitation in a vertical tube

The flooding phenomenon has an important influence on the safety of equipment, especially the nuclear power plant. A new semi-empirical correlation for flooding was proposed based on the experimental investigation of the physical characteristics of the flooding in our previous work. The model was derived from the momentum equations in the annular flow model. The liquid volume fraction, the wall and interfacial friction have been taken into account. The interfacial friction factor is emphatically discussed in this study since the interfacial friction has a significant influence on flooding. A modified model of interfacial friction factor was presented containing the Bond number since the Bond number can remove the influence of the geometry. The predicting error was basically within 20% compared with the existing experimental data obtained in different geometries and sizes.