FLOW DYNAMICS AND HEAT-TRANSFER OF A CONDENSATE FILM ON A VERTICAL WALL .2. FLOW DYNAMICS AND HEAT-TRANSFER

The effects of waves occurring on a falling condensate film on heat tr ansfer have been studied by direct computer simulation. The time-depen dent Navier-Stokes and energy equations, as well as the Poisson equati on for pressure, have been solved for a condensate film of R11 from th e leading edge to 0.6 m with finite difference schemes and non-periodi c boundary conditions The waves, which have amplitude of the order of the film substrate, were observed in the region of 200 < Re < 455, and the heat transfer coefficient is increased by about 60%, while it is identical with the Nusselt theory at Re < 120. In this simulation rang e the enhancement of the heat transfer is attributed to the decreasing time averaged film thickness due to waves, and the disturbance effect s of the waves are small.