Investigation of the interfacial parameter distribution in a bubbly flow in a narrow rectangular channel under inclined and rolling conditions

Local heat and mass transfer processes are determined to a great extent base on both interfacial parameters and their distribution in two-phase flow systems. The effects of inclination and rolling on the lateral distribution of interfacial parameters for bubbly flow in a narrow rectangular channel were studied experimentally using a high-speed camera. Local parameters such as the bubble proportion, void fraction and interfacial area concentration (IAC) were determined in the experiments. The parameters exhibited similar trends in their distributions. The parameters varied slightly in the central part of the duct and presented peaks at positions of approximately x(i)(w/2) = +/- 0.5 when the channel was vertically oriented for both motionless and rolling cases. The peak values of the local parameters in the lower wall region are reduced, and the peak values near the upper wall increased with increasing inclination or rolling angles. No obvious differences were observed among interfacial parameters in the lateral distribution at the same position under inclined and rolling conditions. This may be because the additional lateral buoyancy induced by the rolling motion is substantially less than the lateral component of the buoyancy caused by gravity, which is a dominating factor in the distribution of interfacial parameters under inclined and rolling conditions. (C) 2014 Published by Elsevier Ltd.