Analysis of the Onset of Dryout Conditions in Diabatic Annular Two-Phase Flows

Abstract

An analysis is presented that predicts the conditions which allow for a formation of a stable dry patch in diabatic annular two phase flows. The analysis employs a force balance formulated for the leading edge of the liquid film. In addition to stagnation, thermo-capillary and vapor thrust forces, the analysis includes effects of the pressure gradient and the interfacial shear stress. It is shown that the equilibrium conditions of a dry patch are dominated by the stagnation force, the surface tension force, the capillary force and the skin drag force. For high heat flux conditions only the first three forces are important.