COMPUTATIONAL SIMULATION AND FLOW PHYSICS FOR STRATIFIED/ANNULAR CONDENSING FLOWS

This work focuses on computational techniques and simulation results for smooth-interface laminar/laminar stratified film condensation on the bottom wall (actively cooled) of an inclined (horizontal to vertical) channel. The full two dimensional numerical solution scheme solves the Navier-Stokes equations in each phase, locates the unknown interface, satisfies all the conditions at the phase­change interface, and satisfies the inlet/outlet/wall conditions. The results for channel flows allow new and improved understanding of the effects of changes in tilt, cooling strategies, exit conditions, entrance conditions and interfacial shear. A useful heat transfer/film thickness correlation is also presented. For downward wavy-interface turbulent/laminar flows inside vertical tubes, this paper briefly describes a one (1­D) and two dimensional (2-D) computational approach.