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Analytical solution for filmwise condensation in confined high-aspect ratio geometry
Ist Teil von
International journal of heat and mass transfer, 2019-04, Vol.133, p.561-571
Ort / Verlag
Oxford: Elsevier Ltd
Erscheinungsjahr
2019
Link zum Volltext
Quelle
Alma/SFX Local Collection
Beschreibungen/Notizen
•Free filmwise condensation in the presence of noncondensables is considered.•Explicit analytical solution for the heat transfer coefficient is obtained.•Thermocapillary stress noticeably flattens the condensate film.
This study revisits the problem of free vapor condensation in the filmwise regime by constructing and solving a comprehensive transport model that describes heat and mass transport through the gas phase, interfacial and thermal resistance of the condensate film, and heat conduction through the cooled wall in a self-consistent manner. We have shown that it is possible to obtain an analytical solution of the model which describes the net condensation flux in the presence of an arbitrary amount of noncondensables. This solution demonstrates that the overall thermal resistance reduces to a sum of the thermal resistances of the wall, the condensate film, the interfacial resistance, and the diffusive resistance of the gas layer only in the limit of infinite thermal resistance of the gas layer, but generally has a more complicated form. Finally, we derived an analytical solution for the condensate film thickness profile which generalizes Nusselt’s classical free condensation solution. Both finite thermal conductivity of the wall and thermocapillary stresses were shown to play an important role, substantially altering the thickness profile.