CSE/CSAR/TAM Seminar

T. G. Theofanous
University of California, Santa Barbara

DATE: Friday, October 22, 2004

TIME: 2:00 P.M.

PLACE: 2240 DCL

TITLE: Compressible Multi-Hydrodynamics: Emergent Needs, Approach, and Status

ABSTRACT

The subject of this talk is multiphase flow under extreme conditions of pressure gradients/transients, and phase differential speeds (kilometers per second). Single-phase as well as multi-phase shocks are important. Reflections/transmission at interfaces, including material interfaces of extremely large density ratios, and acoustic impedance mismatch are important too. We are interested in mixing phenomena and eventual dispersal of the dense phase. Processes of interest may involve pre-existing particulates, or evolving length scales via the breakup of liquid and/or solid masses. The liquids may be Newtonian or viscoelastic, the latter being rendered to varying degrees so by the addition of polymeric substances of varying molecular weight, cross-linking, and concentrations. The length scale evolution defines the degree of coupling, both momentum and energy (cooling or reaction effects, for example). Some of the areas of application include inertial confinement fusion, energetic dissemination of liquids or solids in the atmosphere, targeting of wild-fires using thickened retardants, and innovative designs of rocket propulsion or internal combustion engines.

I will discuss the nature of the issues, the technical challenges, and our overall approach to these problems. a synthesis of experiments, direct numerical simulations, and effective field modeling. I will also give sample results from our three-year-long effort in this area.

BIOGRAPHY

Theofanis (Theo) G. Theofanous is professor in the Chemical Engineering and Mechanical Engineering Departments at UCSB, and Founding Director of the Center for Risk Studies and Safety (CRSS). He is a graduate of the National Technical University of Athens, Greece, and holds a PhD from the University of Minnesota, both in Chemical Engineering. Prior to coming to UCSB in 1985, he taught at Purdue's Chemical Engineering and Nuclear Engineering Departments, where he was also the Founding Director of the Nuclear Reactor Safety Laboratory. Professor Theofanous has worked on basic aspects of multiphase flows and of risk management, and saw applications to completion on important safety, and risk-management issues in both the chemical, and nuclear industries, and as of recently in the domain of national defense. He consulted extensively, and internationally, for industrial and governmental organizations, and served on a number of National Research Council panels, including the one that assessed the safety of the nation's research and production (defense) reactors (nuclear) in the aftermath of the Chernobyl accident. He is a member of the National Academy of Engineering, a fellow of the American Nuclear Society, and he holds an honorary doctorate from the University of Lappeenranta in Finland. In 1997 he received the E. O. Lawrence Medal from the U.S. Department of Energy for his work on managing risks of severe accidents in nuclear power reactors.