International Journal of Heat and Mass Transfer, Vol.38, No.15, 2715-2722, 1995
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 transfer have been studied by direct computer simulation. The time-dependent Navier-Stokes and energy equations, as well as the Poisson equation for pressure, have been solved for a condensate film of R11 from the leading edge to 0.6 m with finite difference schemes and non-periodic 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 range the enhancement of the heat transfer is attributed to the decreasing time averaged film thickness due to waves, and the disturbance effects of the waves are small.