Two-dimensional turbulent film condensation of vapours flowing inside a vertical tube and between parallel plates: a numerical approach

Film condensation of vapour flowing inside a vertical tube and between parallel plates is treated. A methodology is presented to determine numerically the heat transfer coefficients, the film thickness and the pressure drop. The analysis is based on the resolution of the full coupled boundary layer equations of the liquid and vapour phases and does not neglect inertia and convection terms in the governing equations. Turbulence in the vapour and condensate film is taken into account using mixing length turbulence models. An explicit method and an implicit finite difference procedures are described. The calculated results for the condensation of steam in a 24 mm diameter tube are compared with those obtained from Chen's correlation. The heat flow rate for the condensation of R123 flowing between parallel plates obtained from numerical solution are compared with experimental values. The mean heat transfer coefficients for the condensation of vapour mixture R123/R134a are also presented. (C) 2003 Elsevier Science Ltd and IIR. All rights reserved.