Conjugated Heat Transfer at Flow Condensation in Minchannel With Longitudinal Fins

Abstract

A mathematical model for vapor condensation in cylindrical longitudinally finned minichannel has been proposed taking into account all temperature non-uniformity. The model describes annular and rivulet flow regimes until complete grooves flooding. It is shown that when the model does not account for the wall heat conductivity the maximal calculated enhancement of heat transfer is predicted for the “sharp” trapezoidal fins. The most enhanced heat transfer in the case of non-isothermal fins has been obtained for the curvilinear fins of expanded Adamek’s parametric family. When reducing the heat conductivity the curvilinear fins become still more effective in comparison with the trapezoidal fins. The wall non-isothermity is a factor, which cannot be neglected when modeling condensation in a minichannels with finned surfaces.

Two-phase flows in pipes and capillary channels

“…Hitachi produces liquid-cooled portable personal computers [2]. Twophase flows in channels of small cross section are used in membrane fuel cells [7] and in evaporationand-condensation systems of thermal stabilization of space vehicles [8,9]. Devices with microchannels are developed for separation of two-phase flow under terrestrial conditions [10] and under conditions of microgravitation [11].…”