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Updated: Jan 12, 2026
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Visually Based Characterization of the Incipient Particle Motion in Regular Substrates: From Laminar to Turbulent Conditions
Published on: February 22, 2018
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Interfaces as transport barriers in two-dimensional Cahn-Hilliard-Navier-Stokes turbulence
Nadia Bihari Padhan1,2, Rahul Pandit1
1Department of Physics, Indian Institute of Science, Bangalore 560012, India.
Summary
Interfaces in binary-fluid turbulence act as significant transport barriers for tracer particles. These barriers effectively trap particles within droplets, with longer trapping times observed for larger droplet radii.
Area of Science:
- Fluid Dynamics
- Turbulence Studies
- Interface Phenomena
Background:
- Binary-fluid turbulence involves complex interface dynamics.
- Understanding transport across these interfaces is crucial for various applications.
- Lagrangian tracer particles offer a method to study particle dispersion.
Purpose of the Study:
- To investigate the role of interfaces as transport barriers in 2D binary-fluid turbulence.
- To quantify the trapping effect of interfaces on tracer particles.
- To explore factors influencing tracer particle retention within fluid interfaces.
Main Methods:
- Utilized the Cahn-Hilliard-Navier-Stokes (CHNS) system for simulations.
- Employed pseudospectral direct numerical simulations of the 2D CHNS equations.
- Tracked Lagrangian tracer particles released within a droplet of one phase.
Main Results:
- Interfaces were found to act as effective transport barriers, retaining tracers for extended periods.
- The fraction of particles inside a droplet decays exponentially with a decay time proportional to R0^3/2.
- Average first-passage times for tracers were significantly larger compared to transport out of a simple circle.
Conclusions:
- Interfaces in binary-fluid turbulence function as substantial barriers to particle transport.
- Droplet size and interface dynamics (e.g., Okubo-Weiss parameter, perimeter fluctuations) influence tracer trapping.
- The findings provide insights into interfacial transport mechanisms in turbulent two-phase flows.
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