Caustics in turbulent aerosols

@article{Wilkinson2004CausticsIT,
  title={Caustics in turbulent aerosols},
  author={Michael Wilkinson and Bernhard Mehlig},
  journal={EPL},
  year={2004},
  volume={71},
  pages={186-192}
}
Networks of caustics can occur in the distribution of particles suspended in a randomly moving gas. These can facilitate coagulation of particles by bringing them into close proximity, even in cases where the trajectories do not coalesce. The evolution of these caustic patterns depends upon the Lyapunov exponents λ1, λ2 of the suspended particles, as well as the rate J at which particles encounter caustics. We develop a theory determining the quantities J, λ1, λ2 from the statistical properties… 

Figures from this paper

Caustics and clustering in the vicinity of a vortex
We study the formation of caustics in vortex-dominated \flows. We \find that only particles starting within a critical distance of a vortex which scales as the square roots of the particle inertia
The waltz of tiny droplets and the flow they live in
This article describes the dynamics of small inertial particles centrifuging out of a single vortex. It shows the important of caustics formation in the vicinity of a single vortex: both for particle
Intermittency and collisions of fast sedimenting droplets in turbulence
We study theoretically and numerically spatial distribution and collision rate of droplets that sediment in homogeneous isotropic Navier-Stokes turbulence. It is assumed that, as it often happens in
Inertial collisions in random flows
In nature, suspensions of small particles in fluids are common. An important example are rain droplets suspended in turbulent clouds. Such clouds can start to rain very quickly and the reason for
Prevalence of the sling effect for enhancing collision rates in turbulent suspensions
Abstract Turbulence facilitates collisions between particles suspended in a turbulent flow. Two effects have been proposed that can enhance the collision rate at high turbulence intensities:
Clustering of aerosols in atmospheric turbulent flow
A mechanism of formation of small-scale inhomogeneities in spatial distributions of aerosols and droplets associated with clustering instability in the atmospheric turbulent flow is discussed. The
Relative velocities of inertial particles in turbulent aerosols
We compute the joint distribution of relative velocities and separations of identical inertial particles suspended in randomly mixing and turbulent flows. Our results are obtained by matching
Sling Effect in Collisions of Water Droplets in Turbulent Clouds
Abstract The effect of turbulence on the collision rate between droplets in clouds is investigated. Because of their inertia, water droplets can be shot out of curved streamlines of the turbulent
Unmixing in random flows
We consider particles suspended in a randomly stirred or turbulent fluid. When effects of the inertia of the particles are significant, an initially uniform scatter of particles can cluster together.
Clustering of heavy particles in vortical flows: a selective review
Abstract Heavy particles in a turbulent flow tend to leave regions of high vorticity and cluster into regions of high strain. The consequences of such clustering have been studied in a variety of
...
...