NSC Seminar Collision of inertial particles in turbulent flows : how does submillimetric flow properties affect rain precipitation

2006-03-10 13:30 - 2006-03-10 15:00
Alain Pumir (Institut Non Lineaire de Nice)
The transport of particles by a turbulent flow, whose density is significantly different from the particle density gives rise to very inhomogeneous particle distributions. I will review the physics of this effect, called preferential concentration, and explain how it affects the collision rate of droplets in a (turbulent) cloud.I will explain how to characterize the heterogeneous particle distribution, as well as the collision rates, with the help of a lagrangian formulation, i.e., by simply following the trajectories of individual particles. Numerical results obtained with this method will be discussed.