This review paper discusses the dispersion of scalar released from a localized source in turbulent flows. In particular, the review emphasizes the distribution of scalar concentration in conjunction to environmental and industrial applications. Here, both general models of scalar concentration distributions, which appear in the literature and studies on specific aspects of the problem, are presented. Diverse subjects related to statistical descriptions of the scalar diffusion such as: location, size and distribution of the released scalar are discussed. These are characterized through models of probability density function of the scalar concentration and expected mass fraction. Experimental methods such as PIV and PLIF for measuring velocity and scalar concentration in turbulent flows as well as examples of applications are summarized.
- Scalar transport