Flow Patterns and Effects of Liquid Viscosity on The¡¡Flow Pattern Transitions in Vertical Downward Pipeline
£×ang Shuzhong, Lin Zonghu, Wang Yanpeng
(Xi'an Jiaotong University, Xi'an, 710049)

Abstract: The flow patterns of air-oil two-phase flows in a vertical downward pipe were investigated experimentally. The pipe diameter was 29mm, and the oil and air superficial velocity was up to 4m/s and 20m/s, respectively. The flow pattern identifications were carried out by means of the combination of visual observations and analysis for corresponding pressure drop pulsation signals. Investigations express that the flow patterns and their transitions of oil-gas two-phase flow somewhat differed from those of low viscous liquid and gas two-phase flows. Based on the study, the effects of the liquid viscosity on flow pattern transitions were given.
Keywords: two-phase flow, flow pattern transition.