Mathematical Modeling and Simulation for Marangoni Convection by Surfactants in Liquid Falling Film

摘要

References(10) Cited-By(4) In an absorption refrigeration system, it is well known that water vapor absorption into lithium bromide (LiBr) aqueous solution is enhanced by the addition of surfactants. Marangoni convection plays a role but its mechanism has not clearly been understood yet. In the present study, a relation between heat and mass transfer and Marangoni convection was investigated using mathematical modeling and numerical simulation in a falling film type absorber. We used an advanced Marangoni convection model that is able to predict velocity, temperature and mass fraction distribution in a falling film type absorber. Firstly, the effect of Marangoni convection on heat and mass transfer in an absorber was examined. As a result, efficiency of heat and mass transfer was increased due to Marangoni convection. Secondly, analysis for the effects of different operating conditions on an onset of Marangoni convection was carried out. The Marangoni number for the onset of convection decreased as the initial temperature and initial water mass fraction of solution decreased.