Modified Empirical Models for Predicting Liquid Film Thickness in Different-Sized Vertical Pipes


  • Almabrok A. Almabrok Petroleum Engineering Department, Faculty of Engineering, Sirte University, Sirte, Libya.



Liquid film Thickness, Gas-Liquid, Empirical Models, Large-Diameter


The liquid film thickness is a vital parameter in many engineering applications such as production equipment of oil and gas. Good control of fluid flow in such equipment can lead to maintaining a continuous liquid film on the pipe wall and hence increasing the anticipated production rate and avoiding catastrophic consequences. Therefore, a precise estimation of liquid film behavior is required to achieve the targeted production rate and overcome the above-mentioned issues.

Even though a considerable number of empirical models were reported, most of these assessed the fluid flow based on small-sized pipes. These models incorrectly predicted the film thickness if applied to a large-diameter.

This work was aimed at developing correlations for gas-liquid two-phase fluid in order to be applicable for different-sized pipes. The new correlations were evaluated against a wide range of experimental data of liquid film and for different diameters collected from the literature on vertical pipes. It was found that the new correlations can be precisely used for predicting the liquid film behavior in small and large pipe diameters.


Ambrosini, W., Andreussi, P & Azzopardi, B J, (1991). A physically based correlation for drop size in annular flow. International Journal of Multiphase Flow, 17(4), pp.497–507.

Ariyadasa, U. (2002). An investigation of film thickness and pressure in upward and downward annular two-phase flow. M.Sc. thesis, Department of Mechanical Engineering, University of Saskatchewan.

Asali, J.C., Hanratty, T J & Andreussi, Paolo, (1985). Interfacial drag and film height for vertical annular flow. AIChE Journal, 31(6), pp.895–902.

Dukler, A. E., Bergelin, O. P. (1952). Characteristics of flow in falling films. Chemical Engineering Progress, 48, pp. 557-563.

Fukano, T. & Furukawa, T., (1998). Prediction of the effects of liquid viscosity on interfacial shear stress and frictional pressure drop in vertical upward gas-liquid annular flow. International Journal of Multiphase Flow, 24(4), pp.587–603.

Henstock, W.H. & Hanratty, Thomas J, (1976). The interfacial drag and the height of the wall layer in annular flows. AIChE Journal, 22(6), pp.990–1000.

Hewitt, G.F. & Govan, A.H., (1990). Phenomenological modelling of non-equilibrium flows with phase change. International Journal of Heat and Mass Transfer, 33(2), pp.229–242.

Hewitt, G.F. & Hall-Taylor, N.S., (1970). Annular two-phase flow,, Oxford; New York: Pergamon Press.

Hori, K. et al., (1978). Study of ripple region in annular two-phase flow (Third report, effect of liquid viscosity on gas-liquid interfacial character and friction factor). Trans. Jap. Soc. Mech. Eng., 44(387), pp.3847–3856.

Kaji, R. & Azzopardi, B.J., (2010). The effect of pipe diameter on the structure of gas/liquid flow in vertical pipes. International Journal of Multiphase Flow, 36(4), pp.303–313.

Kelessidis, V. C. and Dukler, A. (1989). Modelling flow pattern transitions for upward gas-liquid flow in the vertical concentric and eccentric annulus. International Journal of Multiphase Flow, 15, pp.173-191.

Kosky, P.G., (1971). Thin liquid films under simultaneous shear and gravity forces. International Journal of Heat and Mass Transfer, 14(8), pp.1220–1224.

Laurinat, J. E., Hanratty, T. J. and Dallman, J. C. (1984). Pressure drop and film height measurements for annular gas-liquid flow. International Journal of Multiphase Flow, 10, pp. 341-356.

MacGillivary, R.M. & Gabriel, K.S., (2003). A study of annular flow film characteristics in microgravity and hypergravity conditions. Acta Astronautica, 53(4–10), pp.289–297.