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Gaussian wave packets in a semi-infinite capillary jet for droplet isolation: Spatial linear analysis and nonlinear
Y M Zhang1,2, H González3, F J García de Bollullos4
1Harbin Institute of Technology, School of Energy Science and Engineering, Harbin 150001, People's Republic of China.
Physical Review. E
|February 20, 2026
Summary
Applying a velocity pulse to a liquid jet can isolate single droplets. A semi-infinite jet model confirms Gaussian wave packets are optimal, revealing phenomena like phase shifts in droplet formation.
Area of Science:
- Fluid Dynamics
- Nonlinear Dynamics
- Microfluidics
Background:
- Single droplet isolation from liquid jets is crucial for various applications.
- Previous studies modeled jets as infinite columns, identifying Gaussian wave packets as optimal for droplet breakup.
- A more realistic semi-infinite jet model is needed to validate prior findings and explore new phenomena.
Purpose of the Study:
- To validate the infinite-jet model using a semi-infinite jet model.
- To identify new phenomena in droplet formation using a semi-infinite jet.
- To investigate the spatiotemporal evolution of Gaussian wave packets in semi-infinite jets.
Main Methods:
- Linear spatial analysis of a semi-infinite jet subjected to a Gaussian oscillatory velocity pulse.
- Nonlinear numerical simulations to model the jet's behavior.
- Parameter fitting to describe Gaussian wave packet evolution and comparison with infinite-jet predictions.
Main Results:
- The semi-infinite jet model confirms the validity of the infinite-jet model for small amplitudes.
- Gaussian wave packets form, advect, and disperse similarly to the infinite-jet model.
- A phase shift in the carrier wave was observed, explainable by stimulation and transient times, and correctable with initial phase adjustment.
Conclusions:
- The semi-infinite jet model supports the efficacy of Gaussian wave packets for droplet isolation.
- Discrepancies, like phase shifts, provide deeper insights into droplet formation dynamics.
- Controlled droplet breakup with symmetrical patterns is achievable, aiding single droplet isolation techniques.
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