TURBULENT DIFFUSION FROM SOURCES IN COMPLEX FLOWS.

Abstract

The dispersion of matter and heat in turbulent flows is generally analyzed in different ways depending on whether the matter and heat are released from distributed sources, such as heat at the wall of a pipe, or whether (as in this review) they are released from a single source that is small compared with the scale of the flow. The aim of this review is primarily to summarize the current ideas and theories about the basic mechanisms for dispersion from localized sources in complex turbulent flows. A brief consideration of the examples already given indicates some of the characteristic features of such flows: inhomogeneity and unsteadiness of the turbulence, the shear and the convergence and divergence of the mean flow, the non-Gaussianity of the turbulence, recirculation of the mean flow, and the presence of surfaces. Refs.