Ultrasound-modulated twin-fluid atomization of a liquid jet

Area of Science:

• Fluid Dynamics
• Aerosol Science
• Surface Physics

Background:

• Taylor's dispersion relation is a foundational model for liquid jet atomization.
• Understanding droplet size and distribution is critical for applications like combustion and spray coating.
• Existing models often do not fully account for air flow effects on liquid surface dynamics.

Purpose of the Study:

• To develop a resonant liquid capillary wave theory incorporating air flow sheltering effects.
• To experimentally validate the theory by investigating droplet size and distribution in twin-fluid atomization.
• To explore the role of ultrasound modulation in controlling atomization characteristics.

Main Methods:

• Extending Taylor's dispersion relation to include surface inclination effects due to air flow.
• Conducting experiments on airblast and ultrasound-modulated twin-fluid atomization of a 2 cSt kinematic viscosity liquid.
• Comparing theoretical predictions of capillary wave growth rates with experimental drop-size and size distribution data.

Main Results:

• The developed theory accurately predicts the relative growth rates of capillary waves.
• Experimental results show good agreement with theoretical predictions.
• Taylor-mode breakup of capillary waves was identified as a dominant mechanism in twin-fluid atomization.

Conclusions:

• The resonant liquid capillary wave theory provides a robust framework for understanding twin-fluid atomization.
• Ultrasound modulation offers a method to control droplet size and distribution in atomization processes.
• The findings have significant implications for optimizing fuel combustion, spray drying, and spray coating technologies.