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

Upward interfacial friction factor in gas and high-viscosity liquid flows in vertical pipes

“…The author treated liquid film interface as form of pipe wall roughness and derived a correlation, which is function of non-dimensional liquid film thickness for prediction of interfacial friction factor (Table 1) (Wallis, 1969). However, the Wallis correlation is valid over a small range of roughness (Pan et al, 2015) and for film thicknesses in the low interfacial shear stress region (Aliyu et al, 2017).…”

“…Several modifications have been made to the Wallis correlation with a view to extend its prediction efficiency over data obtained for larger range of film thickness as they became available (Moeck, 1970;Henstock and Hanratty, 1976;Fore et al, 2000;Belt et al, 2009;Pan et al, 2015) and also to improve their predictions. Modifications largely consist of subtle changes in the structure; introduction of new constants (Moeck, 1970) and introduction of dimensionless numbers -gas bulk Reynolds numbers (Asali et al, 1985;Lopes and Dukler, 1986;Fore et al, 2000), Froude numbers (to demonstrate the dependency of interfacial friction on Reynolds numbers and Froude Numbers) (Pan et al, 2015), a viscosity ratio to account for the effect of liquid viscosity (Fukano and Furukawa, 1998) as well as offsets in the ( / ) ratio (Fore et al, 2000).…”

Interfacial Friction Factor Prediction in Vertical Annular Flow Based on the Interface Roughness

“…An experimental database (Tab. ) for the interfacial friction has been built through collecting the experimental data published in the open literature , . It consists of six individual experiments with the pipe diameter D ranging from 19 to 50.8 mm, the superficial gas Reynolds number Re sg from 7770 to 186 000, and the superficial liquid Reynolds number Re sl from 80 to 12 350.…”

“…The correlations of Asali, Ambrosini, and Holt belong to the third category because the prediction region is divided based on the liquid film Reynolds number . Wongwises, Belt, and Pan proposed empirical correlations based on the fitted experimental data , , . These correlations are classified as the fourth category.…”

“…) , . The wave height plays a decisive role , . Due to the difficulty in predicting the wave height, the liquid film thickness δ has been widely used.…”