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Memory effects in chaotic advection of inertial particles

A systematic investigation of the effect of the history force on particle advection is carried out for both heavy and light particles. General relations are given to identify parameter regions where the history force is expected to be comparable with the Stokes drag. As an illustrative example, a paradigmatic two-dimensional flow, the von Kármán flow is taken. For small (but not extremely small) particles all investigated dynamical properties turn out to heavily depend on the presence of memory when compared to the memoryless case: the history force generates a rather non-trivial dynamics that appears to weaken (but not to suppress) inertial effects, it enhances the overall contribution of viscosity. We explore the parameter space spanned by the particle size and the density ratio, and find a weaker tendency for accumulation in attractors and for caustics formation. The Lyapunov exponent of transients becomes larger with memory. Periodic attractors are found to have a very slow, ${{t}^{-1/2}}$ type convergence towards the asymptotic form. We find that the concept of snapshot attractors is useful to understand this slow convergence: an ensemble of particles converges exponentially fast towards a snapshot attractor, which undergoes a slow shift for long times.

Titel: Memory effects in chaotic advection of inertial particles
Verfasser: Daitche, Anton
Tél, Tamás
Dokumenttyp: Artikel
Medientyp: Text
Erscheinungsdatum: 04.07.2014
Publikation in MIAMI: 11.12.2014
Datum der letzten Änderung: 16.04.2019
Quelle: New Journal of Physics 16 (2014) 7, 1-30, 073008
Fachgebiete: Physik
Lizenz: CC BY 3.0
Sprache: Englisch
Anmerkungen: Finanziert durch den Open-Access-Publikationsfonds 2014/2015 der Deutschen Forschungsgemeinschaft (DFG) und der Westfälischen Wilhelms-Universität Münster (WWU Münster).
Format: PDF-Dokument
URN: urn:nbn:de:hbz:6-91319457739
DOI: doi:10.1088/1367-2630/16/7/073008
ISSN: 1367-2630