John Tsamopoulos

University of Patras

Chemical Engineer

Fellow, Elected 2022

John Tsamopoulos is a professor in the Dep. of Chemical Engineering at the University Patras and Director of the Laboratory of Fluid Mechanics and Rheology, since 1993. Prior to joining UP he served in the Faculty of the Department of Chemical Engineering in the State University of New York for 9 years reaching the rank of full Professor. Prof. Tsamopoulos received his Diploma in Chemical Engineering from the National Technical University of Athens in June 1979, and his M.S. and Ph.D. degrees in Chemical Engineering from MIT, in June 1981 and January 1985, respectively. He spent the spring of 2016 as a Nelder Visiting Fellow, in the Departemnt of Mathematics, at Imperial College.

Early in his career, he worked with his research group on free boundary problems and examined the dynamics of drops, bubbles, and liquid bridges. Subsequently, he studied various polymer processing operations such as extrusion, film blowing, gas assisted injection molding using various viscoelastic fluid models. With Beris he studied the falling sphere in a Bigham fluid, which is a fundamental problem and resulted in one of the most oft-cited works in the literature of these materials. More recently he examined the importance of elastic forces in yield stress fluids and verified that they cause the loss of the fore‐aft symmetry observed even under creeping flow. With his graduate student, Varchanis, he developed a new Petrov‐Galerkin stabilized Finite Element formulation for viscoelastic flows that allows the use of equal order linear interpolants for all variables and simultaneously does not suffer from the high Weissenberg number problem. With these novel numerical tools, he analyzed the underlying physics related to the appearance of surface distortions on polymer melt extrudates, often referred to as “sharkskin” instability. He attributed them to the intense stretch of polymer chains and subsequent recoil at the region where the melt detaches from the die wall.

Prof. Tsamopoulos was a Founding Member of the Hellenic Society of Rheology (HSR) and served as its 1st Secretary and then as its President. He has served in the Editorial Board of several Journals including JNNFM since 2002 and PoF since 2019. Along with Vlassopoulos he edited a special issue of JNNFM, dedicated to Acrivos on the occasion of his retirement from the Levich Institute and CCNY. The papers were among those presented during the 3rd International conference of HSR, which took place in Patras (June 2001) and was organized by him. He is a fellow of the American Physical Society. He has received the “Bingham fluid medal” during the 6th International Conference on Viscoplastic Fluids: From Theory to Application (2015). Six of his papers have been selected as Editor’s choice and one of them was awarded the 2018 Walter’s Prize. He has been a Member of the National Advisory Research Council of the Ministry of Development of Greece. He is the chairman of the organizing committee of the 14th European Fluid Mechanics Conference (EFMC14), which will take place in September 2022, in Athens, Greece. His role as a mentor of future researchers is notable, because six of his former Doctoral students and post‐Doctoral associates are currently Faculty members. His 131 Journal publications have received 3555 citations, with h=32, (WoS).