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Separation of heavy particles in turbulence
1Racah Institute of Physics, Hebrew University of Jerusalem, Jerusalem 91904, Israel.
Physical Review Letters
|March 21, 2008
Summary
We study particle motion in turbulent flows. Inertia causes particles to drift, leading to rapid fluctuations in their separation dynamics, described by a new Langevin model.
Area of Science:
- Fluid dynamics
- Turbulence
- Particle transport
Background:
- Particle dynamics in turbulent flows are complex.
- Inertia influences particle drift relative to fluid.
- Understanding particle separation is crucial for various applications.
Purpose of the Study:
- To investigate the motion of small particles in turbulence.
- To analyze particle drift and separation dynamics.
- To develop a theoretical framework for particle behavior.
Main Methods:
- Studying particle relaxation times within inertial scales.
- Introducing a Langevin description for separation dynamics.
- Analyzing Lyapunov exponent and Richardson's law analogue.
Main Results:
- Collective drift of close particles causes rapid velocity increment fluctuations.
- A Langevin model accurately describes particle separation dynamics.
- An analogue of Richardson's law for separation above the viscous scale is derived.
Conclusions:
- Particle inertia significantly impacts separation dynamics in turbulence.
- The developed Langevin model provides insights into particle dispersion.
- The findings extend understanding of particle behavior in turbulent environments.
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