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Extreme Small-Scale Clustering of Droplets in Turbulence Driven by Hydrodynamic Interactions
M A Yavuz1, R P J Kunnen1, G J F van Heijst1
1Fluid Dynamics Laboratory, Department of Applied Physics and J. M. Burgers Center for Fluid Dynamics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, Netherlands.
Physical Review Letters
|June 30, 2018
Summary
In turbulent airflow, droplets exhibit preferential concentration and extreme clustering at small scales. This study explains this clustering using fluid dynamics principles and particle inertia.
Area of Science:
- Fluid Dynamics
- Turbulence
- Particle Physics
Background:
- Inertial particles in turbulent flows are known to concentrate preferentially.
- The behavior of droplets at the smallest scales in turbulence requires further investigation.
Purpose of the Study:
- To investigate the clustering of droplets in turbulent airflow.
- To theoretically explain the observed extreme clustering at small scales.
Main Methods:
- Three-dimensional particle tracking measurements were employed.
- Theoretical analysis utilized Stokes-flow dynamics for two spheres and perturbative small-inertia expansion.
Main Results:
- Droplets showed preferential concentration, consistent with known phenomena.
- An additional, extreme clustering was observed at the smallest scales.
Conclusions:
- The study confirms preferential concentration of droplets in turbulence.
- A theoretical framework was developed to explain the novel small-scale clustering phenomenon.
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