BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:On the relevance of Reynolds stresses in linear analyses of turbul
 ent flows - Carlo Cossu (CNRS (Centre national de la recherche scientifiqu
 e))
DTSTART:20220331T090000Z
DTEND:20220331T093000Z
UID:TALK171197@talks.cam.ac.uk
DESCRIPTION:There is a growing body of evidence that the nature of wall-bo
 unded turbulence can be associated to a continuum of nonlinear self-sustai
 ned dynamical processes whose kinematic counterparts in the logarithmic la
 yer are Townsend's attached eddies. Linear energy amplification mechanisms
  play an important role in these dynamical processes and in the selection 
 of the most energetic turbulent structures. I will argue that the definiti
 on of the linear operator\, and in particular the inclusion (or not) of th
 e effect of Reynolds stresses in it\, has profound consequences on linear 
 analyses of the amplifications of mean flow perturbations. It will be show
 n that second-order correlations can be well predicted by suitably modelin
 g Reynolds stresses in resolvent analyses of constant-density turbulent ch
 annel flows where no information is available on forcing statistics. It wi
 ll be also shown that the same type of modeling is necessary to predict th
 e onset of turbulent large-scale convection in unstably stratified turbule
 nt channels.
LOCATION:Seminar Room 1\, Newton Institute
END:VEVENT
END:VCALENDAR