Analytical and Level Set Method-Based Numerical Study for Two-Phase Stratified Flow in a Pipe

Abstract

A nondimensional analytical study for fully developed and three-dimensional numerical study of developing viscosity stratified flow is presented, at various values of viscosity ratio η, inlet area fraction of the less viscous fluid α 1,in , and Reynolds number. With increasing α 1,in , a change in the trend of axial variation in interface–from inlet to the fully developed region–is found at α 1,in = α 1,in,c . With increasing η, development length is found to asymptotically decrease for α 1,in = 0.2 and increase for α 1,in = 0.5 and 0.8. A physical model for flow development is also presented for single- and two-fluid flow. A favorable operating condition to reduce the cost of transportation of more viscous fluids by pipe is proposed.