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Dr. Evgeny Asmolov Central Aerohydrodynamic Inst. (TsAGI), Zhukovsky February 18rd, 2016 |
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SEMINAR ABSTRACT:Rigid spherical particles in shear flows at small particle Reynolds numbers experience a lift (Saffman force) which is due to small advective terms in Navier-Stokes equations. This force results in particle migration across the streamlines of carrier fluid. The inertial migration is widely used in bio- and medical applications to sort, separate or focus particles. Flow induced by a particle is investigated using the method of matched asymptotic expansions. The lengthscale of an inner region is a particle radius. Flow in this region, to the leading order of Reynolds number, corresponds to the classical Stokes solution. Flow in an outer region with much greater lengthscale is governed by linear Oseen-like equations which are solved using Fourier transforms. The lift is evaluated for various shear flows (linear wall-bounded flow and plane channel flow), directions and magnitudes of slip velocity. The stable equilibrium positions where the lift vanishes are determined. Asymptotic solution for the disturbance flow far from the particle is obtained, including an inviscid region and viscous wakes. The flow of dispersed phase under the Stokes drag and inertial lift in gas laminar boundary layers is investigated. |
SPEAKER INTRODUCTION:Dr. Evgeny S. Asmolov has received his MSc (1981) and Ph.D. (1986) from the Moscow Institute of Physics and Technology. He joined in 1981 the group of Mikhail N. Kogan at the Laboratory of Rarefied-Gas Dynamics, Zhukovsky Central Aero-Hydrodynamics Institute (TsAGI), as a research fellow. Since 1999 he is a leading research fellow at the Central Aero-Hydrodynamics Institute. He spent several visits as an invited professor at Ecole Superieure de Physique et Chemie Industrielle (Francois Feuillebois). During 2007-2010 he got a scientific consultant position at the Schlumberger Moscow Research. Since 2004 E.S.Asmolov joined the Laboratory of Multiphase Flows (A.N. Osiptsov) of the Institute of Mechanics of Moscow State University, and since 2010 he is a senior research fellow of the Laboratory of Physical Chemistry of Modified Surfaces at the A.N.Frumkin Institute of Physical Chemistry and Electrochemistry. His research is focused on the dynamics of small particles in fluid, on the stability of suspension flows and on flows past super-hydrophobic walls. |