An analytical study on interfacial wave structure between the liquid film and gas core in a vertical tube

• Published in: International journal of multiphase flow Vol. 30; no. 7; pp. 827 - 851
• Main Authors: Inada, F., Drew, D.A., Lahey, R.T.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-07-2004; Elsevier
• Subjects: Annular flow; Dispersion relation; Exact sciences and technology; Flows in ducts, channels, nozzles, and conduits; Fluid dynamics; Fundamental areas of phenomenology (including applications); Interfacial waves; Linear stability analysis; Long wave theory; Multiphase and particle-laden flows; Multiphase flow; Nonhomogeneous flows; Physics; Soliton; Taylor bubble; Traveling wave; Two-fluid model; Multiphase flow; Interfacial waves; Dispersion relation; Soliton; Traveling wave; Long wave theory; Linear stability analysis; Taylor bubble; Annular flow; Two-fluid model; Gas liquid interface; Bubbles; Travelling waves; Wave propagation; Two-phase flow; Vertical pipe; Solitons; Theoretical study; Linear stability; Analytical solution
• ISSN: 0301-9322; 1879-3533
• DOI: 10.1016/j.ijmultiphaseflow.2004.03.002

A model has been derived for interfacial wave propagation for a liquid film on the wall of a vertical pipe and for a flowing gas in the central core. An analytical study is presented for the stability of a flat interface, and for traveling waves on the interface. Long wave theory is applied to both phases and the resulting conservation equations are of the same form as a two-fluid model. Two situations are examined: the interface between a Taylor bubble and the liquid film, where the gas velocity is small, and the interface for cocurrent annular flow where the gas velocity is relatively large. The interface between a Taylor bubble and a liquid film was found to be dominated by waves, which can be destabilized by the inertia of the liquid phase. For annular flow the interface is subject to a Kelvin–Helmholtz instability. When the gas flow rate is small, and surface tension is negligible, the traveling wave has a shape similar to that of a Taylor bubble except near the tip and trailing edge. When surface tension is dominant, the solution is a soliton. This region and the receding part of the soliton appears to be related to the ripple waves seen near the trailing edge of Taylor bubbles.