LEVICH INSTITUTE SEMINAR ANNOUNCEMENT, 04/27/2004
Steinman Hall, Room #312
(Chemical Engineering Conference Room)
Professor Vladimir Entov
Institute for Problems in Mechanics of the Russian Academy of Sciences
"Dynamics and Breakup of Sheets, Jets and Filaments of Elastic Liquids"
Dynamic experiments with sheets, capillary jets, falling drops and thin filaments of elastoviscous fluids, such as solutions of polymers or surfactants, provide an unique opportunity to probe fluid behaviour under extremal circumstances. In these simple and easy-to-observe free-boundary flows dynamics and breakup are drastically modified by minute amounts of macromolecular substances. In jets and filaments these effects are caused by strong elongation of macromolecules along the axis and development of transient elastic stress that stabilizes liquid filament and prevents its fast rupture by capillary forces. Different manifestations of this basic mechanism are demonstrated, including new ones revealed by high-speed visualization experiments. Experimental observations are analyzed using one-dimensional dynamic theory, and it is shown that these experiments provide important information on elastic properties of macromolecules and their limiting behavior up to breakup. Some open issues are also discussed briefly, including proper statement of the problem of dynamics of a free jet breaking into drop and a liquid rupture problem and liquid rupture criteria.
The talk is based on collaborative studies with A.Bazilevsky, A.Rozhkov, A.Yarin, J.Hinch, J.Bico, C.Clasen and G.McKinley.
BRIEF ACADEMIC/EMPLOYMENT HISTORY:
CURRENT RESEARCH INTERSTS: