Two phase flow

Two phase flows occur in a variety of industrial contexts, such as in boilers, condensers, nuclear cooling systems, and fluidised bed sulphide roasters, for example. The (usually two) constituents may be gas and liquid, such as air/water or steam/water, gas and solid, as in a fluidised bed. Liquid/liquid immiscible flows occur in oil extraction, where oil mixes with water in the borehole. Other examples in nature are in volcanic eruptions, pyroclastic flows, snow avalanches, lahars (mudflows), and sandstorms. Inevitably, the flow is turbulent, and often there is phase transition between the phases (whether via boiling, reaction or dissolution). There are still fundamental issues involved in modelling such flows which are not understood, and there are dynamic phenomena whose full explanation is not available. A simple everyday example is the passage of waves downwards in a settling pint of Guinness. Mathematically comparable waves are seen also in other two phase flows, in rivers, and perhaps even in traffic flow.

Multi-phase flow models can also be used to describe the squeezing of water from paper and the growth of tumours.

People working in this area within OCIAM are