In fluid mechanics, two-phase flow is a flow of gas and liquid — a particular example of multiphase flow.
What is the two phase flow?
Two-phase flow is a flow in which two different aggregate states of a substance or of two different substances are simultaneously present. The possible combinations include gaseous/liquid (see Gas content of fluid handled), gaseous/solid and liquid/solid (see Solids transport).
What is a 2 phase mixture?
A two phase mixture is a mixture of two different substances. An example of a two phase mixture would be a soft drink. It is a liquid and a gas. To separate these two substances you could heat the liquid and then capture the carbon dioxide.