Stability of core-annular flow in the presence of soluble surfactant

Project description

A core-annular flow is a multi-phase flow of two immiscible liquids of different viscosities and/or densities, where one liquid moves through the core of a cylindrical pipe and another liquid forms an annular ring along the wall. Core-annular flows are useful in a wide range of practical applications including oil recovery and transport. In a steady flow the interface separating the two phases is concentric with the pipe wall, but interfacial waves are often required in order to enhance transport. It is possible to control the flow to a desired state by using various techniques, for example by adding chemical compounds called surfactants that affect the interfacial tension. This project will consider a two-layer core-annular flow in a three-dimensional cylindrical pipe. The main objective will be to examine the effect of soluble surfactants on the flow stability and explore the underlying nonlinear dynamics. The project will combine analytical and numerical techniques with aim to develop, analyse and solve appropriate mathematical models for the study of two-fluid core-annular flow with soluble surfactants.