Prediction of the interfacial shear-stress in vertical annular flow

The influences of gas–liquid interfacial properties on interfacial shear stress for vertical annular flow

“…Whereas, the development of the interfacial shear stress model by mean of two-fluid concept was of little concern liquid film characteristics including the waviness of the film. Similar situation was encountered in application of the momentum balance in the axial direction of the gas core to obtain the interfacial shear stress [10,11], although in this connection it was convenient for adding influence factors to the interfacial shear stress such as gravity, entrainment and deposition, etc.…”

“…In pursuit of the influence of entrainment-deposition process and formation of gas eddy on the interfacial shear stress, many references [5,10,11] have devoted the researches to this matter so far. Thereby, the entrainment-deposition process and formation of gas eddy can be implemented directly here.…”

The effect of pipe diameter on the structure of gas/liquid flow in vertical pipes

“…For those data the system pressure varied from atmospheric to 0.15 MPa. The data from Belt et al (2009) for 50 mm and Schadel (1988) for 42 mm were not taken at such high liquid flow rates; therefore the information for their cases was obtained by extrapolation using the regression curve derived from plots of film thickness against liquid superficial velocities and converting to void fraction. Whilst there might be a slight difference in the system pressure between the experiments from different pipe diameters, the void fraction shows little effect of pipe diameter.…”

Disturbance wave development in two-phase gas–liquid upwards vertical annular flow

“…This flow regime corresponds to a situation in which the liquid phase flows in the form of a film on the inside of the conduit wall, in addition to droplets entrained within the gas phase. Understanding the intricate interfacial dynamics of annular flows is important for a number of reasons, which include the ability to predict the frictional pressure drop in two-phase flows (Wallis 1969;Asali et al 1985;Fukano and Furukawa 1998;Fore et al 2000;Wongwises and Kongkiatwanitch 2001;Wang and Gabriel 2005;Belt et al 2009) that dictate pumping requirements, the fraction of liquid entrained in the gas in the form of droplets (Andreussi 1983;Schadel et al 1990;Ambrosini et al 1991;Azzopardi 1997;Pan and Hanratty 2002;Sawant et al 2008a) and the onset of flooding in counter-current configurations (Dukler et al 1984;McQuillan and Whalley 1985;Govan et al 1991;Karimi and Kawaji 2000). Although both upwards and downwards annular flows have been studied in the literature, in this paper we focus on the vertical, upwards (co-current) gas-liquid flow configuration.…”