Effects of channel width on film condensation in a top-closed vertical channel

Abstract

This article conducts a theoretical investigation into the condensation of a saturated vapour within a top-closed, vertical isothermal channel. The theoretical model takes account of the inertia and convection effects in a condensate layer and the shear stress at the liquid—vapour interface. Using a dimensionless transformation method, the complex partial differential governing equations are transformed into a corresponding system of ordinary differential equations, which are then solved using the forward Runge—Kutta shooting scheme. Numerical results indicate that the condensate flowrate decreases and the negative shear stress at the liquid—vapour interface increases as the channel width is reduced. Conversely, a larger channel width increases the shear stress at the channel wall, but has no apparent effect on the temperature profile within the condensate layer.