Hello Paul, Just wondering if you have had some time to think about the issue of including the Marangoni stress in a two-fluid model. Cheers, Frank -- Frank Herbert Muldoon, Ph.D. Mechanical Engineering Technische Universität Wien (Vienna Technical University) Inst. f. Strömungsmechanik und Wärmeübertragung (Institute of Fluid Mechanics and Heat Transfer) Resselgasse 3 1040 Wien Tel: +4315880132232 Fax: +4315880132299 Cell:+436765203470 fmuldoo (skype) http://tetra.fluid.tuwien.ac.at/fmuldoo/public_html/webpage/frank-muldoon.ht...