Direct numerical simulation of wall-to liquid heat transfer in dispersed gas-liquid two-phase flow using a volume of fluid approach

In this paper a simulation model is presented for the direct numerical simulation (DNS) of wall-to-liquid heat transfer in dispersed gas-liquid two-phase flow using a volume of fluid (VOF) approach. Our model extends the VOF model developed by Varl Sint Annaland et al (2005) to non-isothermal conditions. Our VOF method involves an interface reconstruction technique based on piecewise linear interface representation. The surface tension is incorporated using a three-dimensional version of the continuous surface force (CSF) model of Brackbill et al. (1992). The model is applied to predict the heat exchange rate between the liquid and a hot wall kept at a fixed temperature. It is found that, due to bubble induced agitation in the liquid phase, the heat transfer rate between the wall and the liquid is considerably enhanced especially when bubble coalescence prevails in the vicinity of the hot wall. Although this finding is obvious from an intuitive point here we present quantitative results to describe this phenomenon. (C) 2013 Elsevier Ltd. All rights reserved.