Hostname: page-component-cd9895bd7-8ctnn Total loading time: 0 Render date: 2025-01-05T16:44:59.491Z Has data issue: false hasContentIssue false
  • English
  • Français

Statistical mechanical description and modelling of turbulent collision of inertial particles

Published online by Cambridge University Press:  25 July 2000

LIAN-PING WANG ,
ANTHONY S. WEXLER  and
YONG ZHOU
LIAN-PING WANG
Affiliation:
Department of Mechanical Engineering, 126 Spencer Laboratory, University of Delaware, Newark, DE 19716-3140, USA; e-mail: [email protected]
ANTHONY S. WEXLER
Affiliation:
Department of Mechanical Engineering, 126 Spencer Laboratory, University of Delaware, Newark, DE 19716-3140, USA; e-mail: [email protected]
YONG ZHOU
Affiliation:
Department of Mechanical Engineering, 126 Spencer Laboratory, University of Delaware, Newark, DE 19716-3140, USA; e-mail: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

The collision rate of monodisperse solid particles in a turbulent gas is governed by a wide range of scales of motion in the flow. Recent studies have shown that large-scale energetic eddies are the dominant factor contributing to the relative velocity between two colliding particles (the turbulent transport effect), whereas small-scale dissipative eddies can enhance the collision rate significantly by inducing local non-uniform particle distribution (the accumulation effect). The turbulent transport effect is most noticeable when the particle inertial response time τp is of the order of the flow integral timescale and the accumulation effect is most pronounced when τp is comparable to the flow Kolmogorov time.

We study these two contributions separately through direct numerical simulations. The two effects are quantified carefully with a numerical procedure that is independent of the computation of average collision rate. This facilitates the study of not only the statistical description of the collision kernel, but also the relative contributions and modelling of the two physical effects. Simulations at several flow Reynolds numbers were performed to suggest a model for the accumulation effect. The data show that the accumulation effect scales linearly with flow Taylor microscale Reynolds number Rλ, while the theory for fully developed turbulence indicates that the maximum level of the turbulent transport effect scales with R1/2λ. Finally, an integrated model has been developed to predict the collision rate at arbitrary flow Reynolds numbers and particle inertia.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 415 , 25 July 2000 , pp. 117 - 153
Copyright
© 2000 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)