ABSTRACT
Two-phase flow can occur in many different components of the nuclear steam supply system including the core, the steam generators, the steam turbines, and the condensers. A flow regime map is a graphical depiction of the state of a two-phase mixture as a function of its velocity and its equilibrium quality x or void fraction a. In power producing systems, the most common example of two phase flow is water and steam. A related example of a three phase flow is water, steam, and air. Flow boiling is the most common form of boiling in nuclear power plants. In general, the convective heat transfer coefficients for flow boiling are much larger than they are for pool boiling. The exact liquid to vapor ratio depends on the temperature of the flow stream, and it also depends on what the vapor temperature inside of the bubbles is relative to the temperature of the surrounding fluid.
