3D Periodic Orbiting of a Photothermal Bubble

Area of Science:

• Fluid Dynamics and Hydrodynamics
• Thermodynamics and Physical Chemistry
• Laser-Matter Interactions

Background:

• Spontaneous periodic oscillations of underwater bubbles are typically limited to one-dimensional (1D) or two-dimensional (2D) motion.
• Achieving three-dimensional (3D) autonomous bubble motion presents significant challenges in fluid dynamics research.

Purpose of the Study:

• To experimentally observe and characterize novel 3D-periodic orbiting bubble motion.
• To elucidate the underlying physicochemical hydrodynamics governing this complex bubble behavior.
• To develop a theoretical framework for predicting and controlling bubble oscillation modes.

Main Methods:

• Experimental generation of 3D-orbiting bubbles using a stationary near-infrared laser focused on hexane.
• Numerical simulations to analyze thermodynamic and hydrodynamic parameters influencing bubble motion.
• Development of a unified physical model and a dimensionless number (Σ=ReSc/Ma) to map bubble motion modes.

Main Results:

• Successful observation of a 3D-periodic orbiting bubble, extending known bubble motion paradigms.
• Attribution of the 3D motion to the interplay between thermal Marangoni effect and thermal buoyancy effect.
• Construction of a phase diagram based on a single dimensionless number, guiding the tailoring of oscillation modes.

Conclusions:

• The study reveals intriguing physicochemical hydrodynamics behind 3D bubble motion.
• Findings provide theoretical guidance for controlling bubble oscillation modes through liquid property manipulation.
• Potential implications for advancing bubble-mediated technologies and understanding complex fluid phenomena.