Effect of eddy diffusivity on turbulent film condensation outside a horizontal tube

The effect of eddy diffusivity upon the turbulent film condensation of saturated vapour flowing downward onto a horizontal isothermal circular tube is performed theoretically by employing the Hilpert semi-empirical model. The interfacial shear of the vapour from laminar flow to turbulent flow is evaluated with help of potential flow theory. The transition region or the separation point of condensate film is also studied for the following different dominant parameters including Prandtl number, Reynolds number, sub-cooling parameters and system pressure parameter. The condensate film flow and the heat transfer characteristics under the effects of eddy diffusivity and the above mentioned parameters are investigated. The present result shows in better agreement with the experimental data than the previous theoretical modes do.