Volume 78, Number 1, April 2007
Article Number 14001
Number of page(s) 5
Section Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics, and Fluid Dynamics
Published online 15 March 2007
EPL, 78 (2007) 14001
DOI: 10.1209/0295-5075/78/14001

The Eulerian description of dilute collisionless suspension

G. Boffetta1, A. Celani2, F. De Lillo3 and S. Musacchio2

1  Dipartimento di Fisica Generale and INFN - Via Pietro Giuria, 1, 10125, Torino, Italy and CNR-ISAC, Sezione di Torino - C. Fiume 4, 10133, Torino, Italy
2  INLN-CNRS - 1361 Route des Lucioles, Sophia Antipolis, 06560 Valbonne, France
3  Fachbereich Physik, Philipps-Universität - Renthof 6, 35032 Marburg, Germany

received 11 October 2006; accepted in final form 15 February 2007; published April 2007
published online 15 March 2007

We analyze the statistical properties of a Eulerian fluid model describing the evolution of a suspension of inertial particles in an incompressible flow. Regularity and compressibility of the velocity field for the inertial phase are investigated in the limit of heavy particles by means of numerical simulations in two- and three-dimensional flows. We show that in the small Stokes number regime the Eulerian fluid model is able to capture fine details of the clustering dynamics, and exhibits good agreement with fully Lagrangian simulations of inertial particle trajectories. The fluid description breaks down due to collisions at Stokes numbers $\gtrsim 0.1$, the actual value depending on the carrier flow characteristics.

47.27.Gs - Isotropic turbulence; homogeneous turbulence.

© Europhysics Letters Association 2007