Oscillatory and chaotic thermocapillary convection in a half-zone liquid bridge

Abstract

Thermocapillary-driven convection in a half-zone liquid bridge was investigated experimentally. The induced flows were categorized into several regimes mainly through the pattern of the suspended particle motion in the bridge and the surface temperature variation. Special attention was paid to the flow structures far beyond the critical condition. Chaotic and turbulent flows were realized in this configuration. They were distinguished from the periodic oscillatory flow by applying the pseudo-phase-space reconstruction from the time series of the surface temperature variation.

Aspect-ratio dependent oscillatory thermocapillary convection in the floating half zone

“…[5]). The similar tendency in the range of 0.58 0.90 A   was also experimentally observed in [9][10][11]. The increasing steepness of the profile may be due to the increasing role of the buoyancy convection in the floating half zone which stabilizes the thermocapillary convection.…”

Assessment of the role of axial vorticity in the formation of particle accumulation structures in supercritical Marangoni and hybrid thermocapillary-rotation-driven flows

“…In such a context, it is convenient to introduce a "spatial way" of thinking, by which the supercritical rotating state of Marangoni flow can be imagined [5][6][7][8][9][10][11][12][13] as the superposition of an axisymmetric toroidal vortex roll (like that existing prior to the onset of 3D flow) and a wave traveling in the azimuthal direction. The two components of vorticity V     in the azimuthal, and axial directions can be written, respectively, as:…”

“…the rotating mode (or traveling wave). The apparently solid filaments, formed by the spontaneous selfassembly of tracer particles, emerge only if the Marangoni number is in a proper range and some specific conditions are satisfied [5][6][7][8][9][10][11] . In particular, Schwabe and coworkers provided some evidence 12,13 supporting the idea that PAS may occur as a resonance between the azimuthally traveling wave and the "turnover time" of the PAS-string in the thermocapillary vortex.…”

Accumulation of particles in time-dependent thermocapillary flow in a liquid bridge. Modeling of experiments

“…The flow must be laminar with a single (azimuthal) mode. Because at very high ∆T the flow undergoes transition to quasi-periodic and turbulent regimes and modes with several co-existing wave numbers m are observed [10], [11], appearance of a PAS is hardly, if at all, possible in such regimes.…”