Numerical study of laminar condensation of downward flowing vapour on a single horizontal cylinder or a bank of tubes

The results of numerical calculations for the downward flow of pure vapour condensing on horizontal tubes are presented. An implicit finite difference method is used. The equality of sheer stress at the liquid-vapour interfac e is used as the coupling condition between the two phases. The inertia and convection terms are retained in the analysis. The vapour phase velocity i s obtained from potential flow. The method of source density distribution o n the body surface is used for the determination of the vapour flow in tube banks. The effect of flooding produced by condensation on upper tubes is t aken into account by assuming that the vapour velocity field is not affecte d by the condensate flow From one tube to another. The results presented sh ow that the vapour boundary layer separation depends on the Froude number. The heat transfer in the intertube space is analyzed and compared with the theoretical and experimental results of other authors. Good agreement is sh own.