Transient condensation of flowing vapor on a flat-plate: A scaling analysis

Abstract

We perform an analysis of condensation of pure vapor flowing over a cooled flat plate. We estimate the time taken to achieve steady-state condensation by a transient analysis where we use results from previous studies that show that the time-dependent behavior is governed by the propagation of a kinematic wave along the condensate film. The steady-state time at any streamwise location along the plate depends on the steady-state film thickness at that location. Classical theories of laminar steady-state condensation are reviewed, and a scaling analysis is performed to capture the scalings for relevant quantities such as the liquid film thickness, liquid velocity, and heat transfer coefficient. The results from the scaling analysis are entirely consistent with the classical theories. Finally, the scaling analysis is extended to take into account effects of turbulence in the liquid film.