Evaporative heat transfer from thin liquid film on a heated cylinder

Simulating a porous surface that is partially saturated with a liquid, a tw o-dimensional meniscus attaching two adjacent cylinders with the same diame ter is studied under heating and convective conditions. A thin liquid film model is presented to predict thin film thickness and evaporative heat tran sfer coefficient. Experiments are carried out to characterize the temperatu re and geometry of a liquid meniscus, The evaporating thin film length is d etermined from measured surface temperature and meniscus shape. The surface temperature data is correlated and used to derive the evaporative heat tra nsfer coefficient with the aid of conjugate heat transfer using a finite el ement code. The results are compared reasonably with the thin film model. T he effects of Bond number, spacing between cylinders and heating power on t hin film geometry and heat transfer characteristics are discussed. Correlat ions to predict the evaporative heat transfer coefficient and ratio of evap orative heat transfer rate to total heat rate are presented. (C) 1999 Elsev ier Science Ltd, All rights reserved.