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Extent

1 digital object.

Description

This experimental study demonstrates MHz-order acoustic control of Rayleigh-regime liquid-jet breakup using a compact through-hole lithium niobate thickness-mode transducer integrated at the nozzle exit and driven near its 6.7 MHz resonance. Jet dynamics were measured by high-speed shadowgraphy at 50,000 fps and breakup lengths were obtained from instantaneous jet-length records using an autocorrelation-based method that identifies statistically separated breakup events. Acoustic actuation produced visible interfacial corrugations and reduced the normalized breakup length for both water and glycerol--water jets. In water, the response was threshold-like at low Weber number and weakened as the jet velocity increased to We ~ 50. A reduced-order threshold correlation, fit to the water amplitude and velocity sweeps, captured this abrupt shortening and the subsequent loss of actuation efficacy. More viscous glycerol--water mixtures shortened immediately at low forcing, indicating a distinct acoustic-coupling regime rather than a universal collapse of the water response. A wetting-control experiment showed that liquid spreading at the nozzle base can also shorten the jet, so the measured response reflects coupled radiation-pressure forcing, capillary-wave feedback, and wetting-mediated disturbance injection. Resolved droplet tracking further showed that MHz excitation changes the visible gate-crossing droplet population, although sub-resolution mist and micron-scale atomization were not measured. These results establish through-hole MHz actuation as a compact route for modifying free-surface jet breakup and provide a repeatable image-analysis protocol for experimental-fluid-mechanics measurements.

Creation Date

• 2025-09 to 2025-12

Date Issued

• 2026

Author

• Nguyen, Kha H. M.

Advisors

• Ahmed, Kareem
• Friend, James

Funding

The authors declare that financial support was received for the research, authorship, and/or publication of this article. This work was supported by funding from the Office of Naval Research, United States, under grant No. 13423461 to J.F. Additional support for K.N. was provided by the STARS Fellowship.

Topics

• Acoustic forcing
• Capillary waves
• Domain: Engineering
• High-speed shadowgraphy
• Liquid jet breakup
• Mechanical engineering
• Plateau-Rayleigh instability
• Reduced-order correlation
• Wetting

Language

• English

Identifier

Identifier: James Friend: https://orcid.org/0000-0003-0416-2165

Identifier: Kha H. M. Nguyen: https://orcid.org/0000-0001-5724-8507