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Making sense of “length-scales” and how they are coupled in high-energy-density plasmas and in the global oceanic circulation

Event Type: 
Date and Time: 
Friday, April 22, 2022 - 16:15
Location: 
Bldg 260, Room 113
Event Sponsor: 
Parviz Moin, Director of Center for Turbulence Research
Speaker(s): 
Professor Hussein Aluie

A "length scale" in a fluid flow does not exist as an independent entity but is associated with the specific flow variable being analyzed. While this may seem obvious, we often discuss the "inertial range" or the "viscous range" of length scales in turbulence as if they exist independently of a flow variable, which in incompressible turbulence is the velocity field. How should we analyze "length scales" in flows with significant density variations, such as across a shock or in multiphase flows? I will discuss different possible decompositions and how only one of them unravels an inertial range of scales in turbulent flows with significant density variations. As an example application, I will describe the energy pathways in Rayleigh-Taylor driven mixing and its implications on implosion modeling at scales of 1—103 micrometers in inertial confinement fusion (ICF). Time permitting, I will preview work we have been pursuing to better understand the coupling between scales of 10—104 km in the global oceanic circulation and its interaction with the winds using satellite observations and global high-resolution simulations.

Bio: 
Dr. Hussein Aluie is an Associate Professor of Mechanical Engineering at the University of Rochester (UofR) and Staff Scientist at the DOE Laboratory for Laser Energetics. He is currently serving as chair-elect of the Group on the Physics of Climate (GPC) within the American Physical Society. Prior to UofR, he was a Center for Nonlinear Studies postdoc at Los Alamos National Laboratory. He earned his PhD from Johns Hopkins University and his BSc from the American University of Beirut. He was awarded the DOE Early CAREER Award in 2019 and selected in 2022 as one of two Young Observers by USNCTAM, which represents the mechanics community on behalf of the US National Academies. His Complex Flow group’s research is inter-disciplinary, spanning oceanography, plasma physics, astrophysics, and applied mathematics. Hussein was born in Beirut, Lebanon and enjoys outdoor sports, live music, and swing dancing.