Formation of Particle Accumulation Structure (PAS) in Half-Zone Liquid Bridge under an Effect of Thermo-Fluid Flow of Ambient Gas

Abstract

Thermocapillary-driven flow is realized in a liquid bridge by a non-uniform surface tension distribution caused by an axial temperature difference. It is known that a unique behavior of the particles suspended in the liquid bridge emerges after the onset of the oscillatory flow states, which is named the particle accumulation structure (PAS) after Schwabe et al (Microgravity Sci. Technol. 1996). In the present study, we focus on one of the two types of the PAS, SL-2 PAS (after Tanaka et al. (Phys. Fluids 2006)), appeared under larger thermocapillary effect. Especially we pay our special attention to the effect of ambient gas flow around the liquid bridge on the SL-2 PAS. We reconstruct the spatio-temporal variations of the trajectory and velocity of the particles on the SL-2 PAS by applying three-dimensional particle tracking velocimetry (3D PTV).