WIT Press


The Collision Rate Of Monodispersed Particles In Turbulent Flows With Gravity

Price

Free (open access)

Paper DOI

10.2495/AFM040231

Volume

45

Pages

7

Published

2004

Size

372 kb

Author(s)

R. Onishi & S. Komori

Abstract

It is of great importance to investigate the collisions of monodispersed particles in turbulent flows both in the mechanical engineering and in the cloud microphysics. A number of previous studies investigated the collision phenomena but they neglected the effect of gravity acting on particles under the assumption of the isotropy of particle motions. However, it is not concluded whether the gravity effect can be neglected or not. In this study, therefore, we investigated the effect of gravity on the collision frequency by using a direct numerical simulation. The results show that the gravity acting on particles decreases the collision frequency, compared to the zero-gravity case. When the terminal velocity of a particle is comparable to or greater than the root mean square value of fluid velocity, the effect of gravity is sign

Keywords