Steady Two-Dimensional Forced Film Condensation with Pressure Gradients for Fluids of Small Prandtl Numbers

A laminar two-dimensional steady forced film condensation with pressure gradients on a nonisothermal surface with (T_sat − T_w) remaining constant is considered. The case of small Prandtl number has been solved. Body force and interface resistance effects have been neglected. Inertia effect for the liquid phase is assumed negligible. Three parameters govern the problem: the pressure gradient parameter β, the property parameter R = (ν_v/ν_l)^1/2, and the parameter B = h_fg μ_v/ΔTK_l. It is found that an increase in pressure parameter, β, results in the decrease of the average Nusselt number, the condensation rate, and the average skin friction coefficient. With or without pressure gradients, the condensation rate and the heat flux increase with the property parameter R. The average Nusselt number, however, decreases with the parameter B to a minimum and then rises again.