CCE Seminar: John Tsamopoulos

Abstract: We consider the buoyancy-driven motion of a single or pair of bubbles that are initially stationary inside an elasto-visco-plastic (EVP) material. Our newly advanced, finite element software is used for the simulations. For the material rheology we use the Saramito-Herschel-Bulkley constitutive model, fitting its properties to a 0.1% aqueous Carbopol solution. The interplay between plasticity, viscoelasticity and inertia is investigated.

Bio: John Tsamopoulos received his Diploma (1979) in Chemical Engineering from the National Technical University of Athens (NTUA) and his MS (1981) and PhD (1985) degrees in Chemical Engineering from MIT (USA) in the areas of Process Dynamics and Fluid Mechanics, respectively. During his PhD he studied the dynamics of drops and bubbles and, on the side, worked along with A. Beris on the "Creeping motion of a sphere through a Bingham plastic". Subsequently, he taught at the State University of New York at Buffalo for 8 years, reaching the rank of Full Professor. He returned to Greece and the Department of Chemical Engineering at the University of Patras in 1993. There, he continued to work on problems related to Polymer Processing, Rheology including flows involving viscoelastic and yield stress fluids, two-phase flow, stability of flows, etc., and has developed along with his group algorithms based on a variety of numerical methods to solve these problems. He has been elected fellow of the American Physical Society (Division of Fluid Dynamics), the Society of Rheology (USA) and the European Mechanics Society (EUROMECH). His papers and presentations along with his graduate students and colleague, Y. Dimakopoulos, have received various awards, such as the Walters Award (twice) from the Journal of non-Newtonian Fluid Mechanics.