International Journal of Heat and Mass Transfer, Vol.83, 465-478, 2015
Vertical channel's heat transfer to the upward foam flow
Paper presents the semi empirical model of the heat transfer process between the internal surface of the vertical channel (tube) and the laminar longitudinal upward macro foam flow. Model is based on the assumption that the amount of the liquid which drains from the macro foam per second in the n vertical zones of the channel is proportional to the nth part of the liquid which comes to the appropriate zone with the foam. The relationship between the foam flow parameters, such like foam flow rate (velocity), volumetric void fraction and temperature was analyzed. Investigation showed that the heat transfer rate monotonically increases with the increase of the foam flow velocity, with decrease of the volumetric void fraction and with increase of the temperature difference between foam flow and channel wall. Comparison of the results of the modeling of the vertical channel with the experimental data, obtained for the vertical flat surface, showed its satisfactory agreement. (C) 2014 Elsevier Ltd. All rights reserved.
Keywords:Semi empirical model;Experimental investigation;Macro foam flow;Heat transfer;Vertical channel;Drained liquid flow;Void fraction