Heat transfer in bubbly downward flow at low gas flow rates

Abstract

The effect of small gas phase additions on heat transfer in downward bubbly flow was shown. Data on the size of bubbles detaching from the edges of an array of capillaries in a liquid flow are given. The influence of the disperse phase dimensions on the heat transfer is discussed. The preliminary data of PIV investigation of liquid velocity distribution is also presented. It is shown that change in the size of the dispersed phase can lead to both intensification and deterioration of heat transfer as compared with a single-phase flow at constant flow rates of liquid and gas at the channel inlet. The mechanism of heat transfer intensification was described early. The cause of the heat transfer deterioration is turbulence suppression in the near-wall region.