An Investigation into the Behavior of Non-Isodense Particles in Chaotic Thermovibrational Flow

Abstract

The ability to control the distribution of particles in a fluid is generally regarded as a factor of great importance in a variety of fields (manufacturing processes, biomedical applications, materials engineering and various particle separation processes, to cite a few). The present study considers the hitherto not yet addressed situation in which solid spherical particles are dispersed in a non-isothermal fluid undergoing turbulent vibrationally-induced convection (chaotic thermovibrational flow in a square cavity due to vibrations perpendicular to the imposed temperature difference). Although the possibility to use laminar thermovibrational flows (in microgravity) and turbulent flows of various types (in normal gravity conditions) to induce the accumulation of solid mass dispersed in a non-isodense fluid is already known, the interplay of finite-size finite-mass particles with chaotic flow in weightlessness conditions has never been considered. In the present study this subject is tackled through direct numerical solution of the fluid and particle tracking equations in the framework of a one-way coupling approach. Results are presented for relatively wide ranges of vibrational amplitude, particle size and density.

On the relationship between solid particle attractors and thermal inhomogeneities in vibrationally driven fluid-particle systems

“…As the present article builds on and, at the same time, it seeks to extend the earlier knowledge accumulated over recent years on these topics, we consider once again the classical cubic cavity in weightless conditions with side having length L examined by Lappa, [27][28][29] Lappa and Burel, 30 and Crewdson and Lappa 37 (no gravity being present, which would otherwise dominate the considered dynamics). As the main motivation for reexamining this kind of problems is the recent discovery of new morphologies in terms of particle structures and related changes in the multiplicity of the attracting loci, 32 a rational generalization of those findings is sought.…”

Characterization of two-way coupled thermovibrationally driven particle attractee

“…As a fleeting glimpse into the existing literature would immediately reveal, the umbrella of ongoing research on this specific subject has essentially drawn on studying the influence of asymmetries present in the considered physical system on this synchronization process (asymmetries due to the shape of container, 57 due to the direction of vibrations with respect to the walls of the cavity, 58,59 or asymmetries spontaneously produced due to time-averaged convective effects, 64 or other mechanisms enabled when the carrier thermovibrational flow displays a certain intrinsic degree of turbulence 65 ). No analysis has been devoted until now to explore another important question, that is, to what extent these delicate structures can survive in non-dilute fluid-particle mixtures.…”