ABSTRACT
A new model is presented for the analysis of hydrodynamics and heat transfer in two-phase annular flow which can be used to predict heat transfer coefficients over the full region from the onset of annular flow to the dryout point.
The model follows the traditional interpretation of evaporative heat transfer, namely that of forced convective film heat transfer which may be enhanced by bubble nucléation processes and growth.
For the forced convective component, a theoretical model for turbulent film heat transfer is used together with the analytical method for annular flow hydrodynamics developed by Owen and Hewitt (1987). The effect of damping turbulence near the interface is also considered, using the analysis of Levich (1962).
For the component of nucleate boiling in the liquid film, the whole hydrodynamic and heat transfer process is considered, from the bubbles growing from active sites to their ultimately bursting through the surface. The model is shown to be consistent with data.
