Forced convection laminar film condensation of downward flowing vapor on asingle horizontal elliptic cylinder or a bank of elliptical tubes

A numerical study is performed on the laminar film condensation of pure sat urated vapor flowing in the direction of gravity on a single horizontal ell iptic cylinder or a bank of elliptical tubes. Temperature, velocity distrib ution, and heat transfer coefficient of the fully developed flow are carrie d out with a fully implicit finite difference scheme. The equality of shear stress at the liquid-vapor interface is used as the coupling condition bet ween the two phases. The inertia and convection term are retained in the an alysis. Outside of the vapor boundary layer, the vapor phase velocity is ob tained from potential flow. The method of source density distribution on th e body surface is used for determination of the external vapor velocity in elliptical tube banks. The effect of inundation produced by condensate on u pper ellipses is taken into account by assuming that the vapor velocity fie ld is not affected by the condensate flow from one elliptic cylinder to ano ther. Based on the obtained solutions of flow field, the effect of surface tension, the interaction because of the ellipse spacing, and the inundation on the heat transfer coefficient and the boundary layer separation point h ave been evaluated. The results of this analysis are discussed especially i n function of eccentricity e (effect of the surface tension). The heat tran sfer in interellipse space is analyzed and compared with the theoretical an d experimental results of other authors. Good agreement is shown.