  Transport phenomena involving condensate liquids generated from the phase
change heat transfer in microchannels and in engineered superhydrophobic
surfaces require consideration of slip effects. In this study, the laminar film
condensation over upward facing flat slabs and circular disks of finite sizes
with free edges in the presence of wall slip effects is investigated. By
considering the Navier slip model and extending the classical Nusselt analysis,
the mass, momentum, and energy of the liquid film in two-dimensional and
axisymmetric coordinates are solved for the film thickness and the heat
transfer rate in non-dimensional form. Numerical solution yields the local
structure of the condensate film profile and the Nusselt number for different
values of the slip coefficient. Investigation of the results reveals that the
condensate film on horizontal surfaces becomes thinner and the overall heat
transfer rate is enhanced with an increase in the slip coefficient. In
particular, a regression analysis of the results indicates a power law
dependence of the Nusselt number on the non-dimensional slip coefficient with
an exponent close to 0.5. Significant enhancement in phase change heat transfer
follow from the modification of the local velocity profiles within the
condensate film, especially in resulting from the additional momentum gain near
the wall surfaces due to increases in slip effects.
