DOUBLE-DIFFUSIVE AND MARANGONI CONVECTION IN A MULTICAVITY SYSTEM

This paper numerically investigates the interaction between the Marang oni and the double diffusive convection in the Maxworthy [Journal of F luid Mechanics, 1983, 128, 259-282] set-up. The model consists of a tw o-cavity rectangular system in which the smaller cavity Ls located at the top left corner of the larger one. The larger cavity is filled wit h hot salty fluid while the smaller one contains cold fresh fluid. Thi s problem is solved for two different cases: the first one contains a rigid upper cavity, thereby, eliminating the Marangoni effect, and the second one contains a free-surface upper cavity. For the latter case, the interaction between the Marangoni (thermal and solutal) and the d ouble diffusive regimes is investigated in detail. Finite element mode lling results indicate that salinity induces stronger convection than the thermal ones. For the case for which a free surface exists, therma l and solutal Marangoni convection further enhances the strength of th e cellular flow. Numerical results agree qualitatively with the Maxwor thy experiment. It is shown that the governing equations should be sol ved in the complete form and that the surface tension should be taken into consideration during the numerical analysis. (C) 1998 Elsevier Sc ience Ltd. All rights reserved.