CONVECTIVE HEAT AND MASS-TRANSFER FROM A FALLING FILM TO A LAMINAR GAS-STREAM

A numerical study has been made of convective heat and mass transfer f rom a falling film to a laminar gas stream between vertical parallel p lates. The effects of gas-liquid phase coupling, variable thermophysic al properties, and film vaporization have been considered. Simultaneou s mass, momentum and heat transfer between liquid film and gas stream is numerically studied by solving the respective governing equations f or the liquid film and gas stream together. The influences of the inle t liquid temperature and liquid flowrate on the cooling of liquid film are examined for air-water and air-ethanol systems. Results show that the heat transfer from the gas-liquid interface to the gas stream is predominantly determined by the latent heat transfer connected with fi lm evaporation. Additionally, better liquid film cooling is noticed fo r the system having a higher inlet liquid temperature or a lower liqui d flowrate.