Interfacial Area Transport of Vertical Upward Bubbly Flow in an Annulus

In relation to the development of the interfacial area transport equation, hydrodynamic separate tests without phase change were performed in an adiabatic air-water bubbly flow in a vertical annulus to identify the effect of bubble coalescence and breakup on the interfacial area transport. A total of 20 data sets on axial developments of local void fraction, interfacial area concentration, and interfacial velocity were acquired by \ud using the double-sensor conductivity probe method in an extensive bubbly flow region. The detailed discussion was given for the mechanism of the axial development of the local flow parameters. The one-dimensional interfacial area transport equation could reproduce proper trends of the interfacial area concentration change along the flow direction and good agreement between predicted and measured interfacial area concentration was obtained with an average relative deviation of 8.96 %