FUNDAMENTAL-ASPECTS OF MODELING TURBULENT PARTICLE DISPERSION IN DILUTE FLOWS

Modeling particle dispersion in turbulent hows is very complex. Severa l publications in this field have dealt with both the experimental and modeling aspects of turbulent particle dispersion. This paper gives a broad overview of different modeling techniques discussed in the lite rature in order to describe the problem of particle dispersion in dilu te flows. Unlike other reviews of this subject, this paper maintains a simple approach in explaining mathematically and conceptually the com plex issues involved in modeling. Some fundamental concepts, such as k ey characteristics of turbulent how and the nature of interaction betw een turbulence and an individual particle under simplified conditions, are discussed. The authors have attempted to present several definiti ons (such as homogeneous flow, stationary condition, and integral time scale) that are commonly used to imply certain assumptions or as conc eptual tools to derive a model. As indicated, a review of models that are capable of predicting the dispersion of dilute concentration of pa rticles in turbulent hows is presented. The models are described in a simplistic way through use of previously explained ideas and concepts. One of the important practical applications of such dilute two-phase how models deals with the problem of pulverized-coal combustion. The f inal part of the paper discusses some of the key issues involved in co mprehensive pulverized-coal combustion models. The primary objective o f this work is to provide a basic understanding of the subject and hen ce to serve as an introduction to the theoretical world of turbulent p article dispersion. Copyright (C) 1996 Elsevier Science Ltd.