TRANSIENT FILM CONDENSATION ON FINITE HORIZONTAL PLATE

Abstract

An analytical study of the transient film condensation on a finite horizontal plate is carried out. The flow across the edges of the horizontal surface is determined by a simple model based on the gravitational force exerted on the fluid. The transient heat transfer to the plate and the growth of the condensate film thickness are determined for various boundary conditions of practical interest. For short times, the semi–infinite solution is considered and it is shown that the solution merges into that for a finite plate thickness as time elapses. The temperature variation across the plate is considered in the analysis of the transient conduction problem and numerical results are obtained to determine the effect of the imposed boundary conditions and the various governing parameters. The results obtained are found to be strongly dependent on the boundary condition at the plate surface. The variation, with time, of the heat transfer to the plate, of the film thickness and of the plate temperature are determined.