Characteristics of one-dimensional bubbly flow interfacial area transport in horizontal narrow rectangular channel

Abstract

The experiments of horizontal adiabatic air-water flow in narrow rectangular channel with a cross-sectional area of 68 mm × 1.9 mm were conducted under an atmosphere pressure condition in order to study bubbly flow interfacial area transport phenomenon. The liquid film thickness was obtained by PCB liquid film sensor. The results show that the liquid film thickness can be correlated with the product of Capillary number Ca and jg/jl, so a correlation for liquid film thickness was proposed. The effect of liquid film thickness on IAC and void fraction was also evaluated. The results show that the average error caused by ignoring liquid film thickness is about 6.1% and 10.1%, respectively. The lateral profiles and axial direction development of the void fraction, interfacial area concentration, bubble Sauter mean diameter were obtained by high-speed camera at three axial locations of Z/D = 63, 241 and 510. The simplified one-dimensional, steady-state, one-group interfacial area transport equation for an adiabatic bubbly flow with six sets of IAC source and sink models was evaluated by the current experimental data. The evaluation results showed that the models of Yao and Morel (2004) and Shen and Hibiki (2013) performed better with mean prediction errors of 12.13% and 18.92%, respectively.