Sling Effect in Collisions of Water Droplets in Turbulent Clouds

By Gregory Falkovich, Alain Pumir. 2006

158 citations recorded by the source corpus.

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 airflow. The contribution of such a “sling effect” in the collision rate of the same-size water droplets is described and evaluated. It is shown that already for turbulence with the dissipation rate 103 cm2 s−3, the sling effect gives a contribution to the collision rate of 15-μm droplets comparable to that due to the local velocity gradient. That may explain why the formulas based on the local velocity gradient consistently underestimate the turbulent collision rate, even with the account of preferential concentration.

Subfields: Computational Mechanics, Earth-Surface Processes, Ocean Engineering

View Paper: https://www.semanticscholar.org/paper/67af363493188075c7b0f40a2df55e425dc1cc40

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Computational Mechanics

In Earth-Surface Processes

In Ocean Engineering

Citations in the corpus

Growth of Cloud Droplets in a Turbulent Environment (2013, background): “The latter has been termed the sling effect (Falkovich et al. 2002, Falkovich & Pumir 2007) or random uncorrelated motion (for a detailed discussion, see Devenish et al. 2012, section 4.2.5).”
Droplet growth in warm turbulent clouds (2012, methodology): “Particularly useful in the study of the latter region has been the so-called fully Lagrangian method (Osiptsov, 2000) and a similar method implemented by Falkovich and Pumir (2004, 2007) and Ducasse and Pumir (2009).”
The effect of Reynolds number on inertial particle dynamics in isotropic turbulence. Part 1. Simulations without gravitational effects (2015, background): “Other researchers have suggested that caustics become more prevalent at high Reynolds numbers, leading to larger relative velocities and thus more frequent particle collisions (Falkovich, Fouxon & Stepanov 2002; Wilkinson et al. 2006).”
Analyzing preferential concentration and clustering of inertial particles in turbulence (2012, background): “The second mechanism which enhances the collision of particles is related to the sling effect due to the formation of caustics (Falkovich et al., 2002; Falkovich and Pumir, 2007) which correspond to regions where particle relative velocity is large.”