Quantitative analysis of particle behavior constituting multiple coherent structures in liquid bridges.

Area of Science:

• Fluid dynamics
• Complex systems

Background:

• Coherent structures, such as Kolmogorov-Arnold-Moser (KAM) tori, can form in closed flows with low-Stokes-number particles.
• Previous research predicted various structures based on Stokes number but did not demonstrate coexistence with multiple particle types.

Purpose of the Study:

• To investigate the coexistence of different coherent structures in a fluid flow system.
• To analyze the composition and attractivity of these structures when multiple particle types are present.

Main Methods:

• Utilized half-zone liquid bridges under normal gravity to create thermocapillary-driven flow.
• Suspended single or multiple types of particles (0.1 mm diameter) and tracked trajectories using synchronized high-speed cameras.
• Quantified particle counts within each coherent structure.

Main Results:

• Demonstrated the coexistence of various coherent structures when particle groups of different diameters were simultaneously suspended.
• Observed that some structures were dominated by a single particle type, while others comprised multiple types.
• Analyzed the 'attractivity' of these structures based on particle composition.

Conclusions:

• The study successfully demonstrated the coexistence of multiple coherent structures in a fluid flow with mixed particle sizes.
• Findings highlight that coherent structures can be selectively composed of single or multiple particle types, influencing their properties.