Prediction of flow profiles and interfacial phenomena for two-phase flow in coiled tubes

The objective of the present study is to investigate the local variables and interfacial phenomena for two-phase flow in coiled tube. We believe that such information is not reported in the open literature and will be helpful for design purposes. A three-dimensional CFD model using volume of fluid (VOF) approach is presented for predicting the development of velocity fields, local and average friction factor, interfacial friction factor, phase distribution and entry length using a commercial CFD package (FLUENT 6.2). The effect of geometrical parameters (curvature ratio, λ = Dc/d; dimensionless pitch, H = p/2πRc) and operating conditions, Dean number, NDe (=NRe(d/Dc)0.5) is also presented. The model predictions are in good agreement with the experimental dataset reported in literature [V. Czop, D. Barbier, S. Dong, Pressure in drop, void fraction and shear stress measurements in an adiabatic two-phase flow in a coiled tube, Nucl. Eng. Des. 149 (1994) 323–333; L.S. Yao, S.A. Berger, Entry flow in a coiled pipe, J. Fluid Mech. 67 (1975) 177–196; L.R. Austin, J.D. Seader, Fully developed viscous flow in coiled circular pipes, AIChE J. 19 (1973) 85–93].