This article needs additional citations for verification. Please help improve this articlebyadding citations to reliable sources. Unsourced material may be challenged and removed.
Find sources: "Preferential concentration" – news · newspapers · books · scholar · JSTOR (December 2009) (Learn how and when to remove this message) |
![]() |
This article may be too technical for most readers to understand. Please help improve ittomake it understandable to non-experts, without removing the technical details. (February 2021) (Learn how and when to remove this message)
|
Preferential concentration is the tendency of dense particles in a turbulent fluid to cluster in regions of high strain (low vorticity) due to their inertia. The extent by which particles cluster is determined by the Stokes number, defined as , where
and
are the timescales for the particle and fluid respectively; note that
and
are the mass densities of the fluid and the particle, respectively,
is the kinematic viscosity of the fluid, and
is the kinetic energy dissipation rate of the turbulence. Maximum preferential concentration occurs at
. Particles with
follow fluid streamlines and particles with
do not respond significantly to the fluid within the times the fluid motions are coherent.
Systems that can be strongly influenced by the dynamics of preferential concentration are aerosol production of fine powders, spray, emulsifier, and crystallization reactors, pneumatic devices, cloud droplet formation, aerosol transport in the upper atmosphere, and even planet formation from protoplanetary nebula.
![]() | This fluid dynamics–related article is a stub. You can help Wikipedia by expanding it. |