ISSN Online: 2377-424X
International Heat Transfer Conference 12
Laminar Film Condensation from Vapour-gas Mixtures in Downward-inclined Parallel-plate Channels
Résumé
A two-phase model is developed to analyze laminar film condensation from mixtures of a vapour and a noncondensing
gas in parallel-plate channels. The channel is inclined down from the horizontal and has an isothermal
cooled bottom plate and an insulated upper plate.
The model under consideration involves the complete two-phase boundary-layer equations including inertia
forces, energy convection, interfacial shear, and axial pressure change. A numerical approach for solving the model
is described using a marching finite-control-volume method. Results are presented for steam-air mixtures in terms
of axial variation of film thickness and local Nusselt number for inclination angles from 0 to 90 degrees. Profiles
of velocity, temperature, and gas mass fraction are also presented. Even a small inclination angle can produce a
significantly thinner film compared to the horizontal orientation. The detrimental effect of noncondensable gas on
the heat transfer rate is relatively greater at lower inclination angles.