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VERSION:2.0
PRODID:-//Memento EPFL//
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SUMMARY:Virtual MEchanics GAthering -MEGA- Seminar: Homogenization-based d
 esign of microstructured membranes: wake flows past permeable shells
DTSTART:20210325T161500
DTEND:20210325T173000
DTSTAMP:20260928T213809Z
UID:a519883a1d3ae1ea9f7d9e6422c0cab5bef8a4363905839c2a879ac7
CATEGORIES:Conferences - Seminars
DESCRIPTION:Pier Giuseppe Ledda (LFMI\, EPFL)\nAbstract All of us have s
 een\, at least once\, flying dandelion fluffs transported by the wind. The
  flow around permeable obstacles is gaining more and more interest owing t
 o its large range of applications. Here\, a formal framework to characteri
 ze and optimize the flow past permeable membranes by means of a homogeniza
 tion approach is proposed and applied to the wake flow past a permeable cy
 lindrical shell.\n\nAn effective stress jump condition is employed to mode
 l the presence of the membrane\, stating that the normal and tangential ve
 locities at the membrane are respectively proportional to the so-called fi
 ltrability and slip numbers. The characterization of the steady flow solut
 ion for several filtrability and slip numbers\, kept constant over the mem
 brane\, shows that the flow morphology is dominantly influenced by filtrab
 ility and exhibits a recirculation region that moves downstream of the bod
 y and eventually disappears as this number increases.\n\nA linear stabilit
 y analysis shows the suppression of vortex shedding as long as large value
 s of the filtrability number are employed. A procedure to obtain the micro
 scopic geometry based on macroscopic objectives is implemented and verifie
 d in case of constant values of filtrability and slip over the membrane. V
 ariations of the filtrability and slip profiles along the membrane are the
 n taken into account and those profiles are optimized to fulfill a given o
 bjective deduced from the flow features in the context of adjoint-based op
 timization. Fast-varying microscopic geometries are finally linked to the 
 optimal profiles via a homogenization-based inverse procedure.\n\nBio PG 
 Ledda is a Ph.D. student at the Laboratory of Fluid Mechanics and Instabil
 ities at the EPFL. He obtained his B.sc and M.sc in Aerospace and Aeronaut
 ical Engineering at the University of Pisa. He joined EPFL during his mast
 er thesis\, focused on the pattern characterization when a porous bluff bo
 dy is invested by an asymptotic flow. He is now focused on the pattern for
 mation in karst environments and the flow modelization using lubrication m
 odels. His main interests involve the flow control of aerodynamic flows by
  porosity variations and of thin films by textured substrates.\n 
LOCATION:https://epfl.zoom.us/s/84678428267 Passcode: 174387 https://epfl.
 zoom.us/s/84678428267
STATUS:CONFIRMED
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