Prediction of heat and fluid flow in microchannel condensation

Abstract

The condensing flow inside the microchannel has gained importance as the microchannel heat exchangers are widely used in the industry. In this study, a number of numerical simulations on condensing flow inside the microchannel were conducted to investigate heat transfer characteristic. Circularmicrochannel geometries with the various diameters were considered. The Volume of Fluid model was used to model twophase flow. The phase change at the saturation temperature was modeled by the Lee model.In the considered geometries, different from the conventional channels, surface tension forces can be importantcomparedto other forces. Therefore, surface tension was considered in the simulations. Constant wall heatflux and constant saturation temperature were applied as simulation conditions, similar to actual operating conditions. The predictions were validated by comparisons with the experimental results that exist in the literature. A satisfactory agreement of the present predictions with the experimental data was observed.