Influence of vaporization by a water reservoir on flows through a corrugated duct

The authors present a numerical and experimental study on heat and mass tra nsfers by forced convection in a channel with a sinusoidal protuberance and by natural convection in a reservoir full of water. The numerical study ha s been carried out for Reynolds numbers in a range of 35 to 350, several de nsities of heat flux and protuberance amplitude range of 0.005 to 0.02 m. R esults show that the vapour diffusion in the air modifies the stream functi on profiles which become convex over the free surface of the water. In addi tion, the evaporation reduces the perturbation caused by the protuberance a nd increases the heat transfer rate in the channel. The visualisation of th e flow, using smoke, an argon laser and a videocamera, shows the complexity of the interaction between the flow of vapour caused by the evaporation, t he flow in the channel and the heat losses across the lateral walls. Theore tical and experimental results are in good qualitative agreement.