BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Memento EPFL//
BEGIN:VEVENT
SUMMARY:Extreme vortex states and the hydrodynamic blow-up problem
DTSTART:20160321T110000
DTEND:20160321T120000
DTSTAMP:20260510T165129Z
UID:3fca0ddec4558c1214eed8b171f73896c9e425def3ccee715f34dd45
CATEGORIES:Conferences - Seminars
DESCRIPTION:Prof. Bartosz Protas\, McMaster University\, Canada\nBio: Prof
 . Protas is an applied mathematician interested primarily in problems comb
 ining modelling\, analysis and computation with the theory of optimization
  and control. He holds a Ph.D. degree awarded jointly by the Warsaw Univer
 sity of Technology and Universite Pierre et Marie Curie (PARIS VI) in 2000
 . After post-doctoral experience at the University of California\, San Die
 go\, he joined the Department of Mathematics and Statistics at McMaster Un
 iversity in Canada as SHARCNET Chair in Scientific Computing\, and has bee
 n on the faculty there since then receiving promotion to the rank of Profe
 ssor in 2015.\nDr. Protas' research is a blend of fundamental investigatio
 ns in core problems of hydrodynamics and applied studies relevant to indus
 trial fluid mechanics and heat transfer\, thermodynamics and electrochemis
 try. He focuses on the use of advanced mathematical methods to develop eff
 icient computational algorithms and models useful for studying complex phy
 sical and electrochemical processes. Dr. Protas has a successful track rec
 ord of industrial collaborations.  A recipient of the Early Researcher Aw
 ard (ERA)\, Dr. Protas has also held several visiting appointments at prem
 ier research universities in Europe and in Asia.  Two of his former Ph.D.
  students (Dr. Bukshtynov and Dr. Ayala) received the dissertation awards 
 of the Canadian Applied and Industrial Mathematics Society (CAIMS) for the
  best doctoral theses in applied mathematics defended at a Canadian univer
 sity\, respectively\, in 2012 and 2014.  Dr. Protas' responsibilities inc
 lude directing the School of Computational Science and Engineering\, one o
 f McMaster's flagship interdisciplinary graduate programs\, and serving on
  the Editorial Boards of the International Journal of Computer Mathematics
  (Section B) and the Journal of Computational Science.http://www.math.mcma
 ster.ca/bprotas\nIn the presentation we will discuss our research program 
 concerning the study of extreme vortex events in viscous incompressible fl
 ows. These vortex states arise as the flows saturating certain fundamental
  mathematical estimates\, such as the bounds on the maximum enstrophy grow
 th in 3D (Lu & Doering\, 2008). They are therefore intimately related to t
 he question of singularity formation in the 3D Navier-Stokes system\, know
 n as the hydrodynamic blow-up problem.\nWe demonstrate how new insights co
 ncerning such questions can be obtained by formulating them as variational
  PDE optimization problems which can be solved computationally using suita
 ble discrete gradient flows. In offering a systematic approach to finding 
 flow solutions which may saturate known estimates\, the proposed paradigm 
 provides a bridge between mathematical analysis and scientific computation
 . In particular\, it allows one to determine whether or not certain mathem
 atical estimates are "sharp"\, in the sense that they can be realized by a
 ctual vector fields\, or if these estimates may still be improved. \nIn t
 he presentation we will review a number of new results concerning 2D and 3
 D flows characterized by the maximum possible growth of\, respectively\, p
 alinstrophy and enstrophy. It will be shown that certain types of initial 
 data\, such as the Taylor-Green vortex\, which have been used in numerous 
 computational studies of the blow-up problem are in fact a particular inst
 ance (corresponding to an asymptotic limit) of our family of extreme vorte
 x states. We will present results comparing the growth of relevant quantit
 ies in high-resolution direct numerical simulations of the Navier-Stokes s
 ystem obtained using our extreme vortex states and different initial data 
 employed in earlier studies.
LOCATION:ME B1 B10 http://plan.epfl.ch/?zoom=20&recenter_y=5864108.22894&r
 ecenter_x=731002.1372&layerNodes=fonds\,batiments\,labels\,information\,pa
 rkings_publics\,arrets_metro\,transports_publics&floor=1&q=ME_B10
STATUS:CONFIRMED
END:VEVENT
END:VCALENDAR