Concentration Distribution in a Turbulent Shear Flow

Abstract

This paper describes a diffusion model for a flow with uniform shear in which the diffusivity tensors are expressed in terms of the statistical correlation tensor of the Lagrangian velocity field by extending Riley and Corrsin's study (1974). The solution of the diffusion equation with these diffusivity tensors cab be expressed as a multinormal distribution function. The asymptotic behavior of the Lagrangian quantities allows the dispersion tensor to be related to the Eulerian turbulent quantities. With these simplifications, the average concentration distribution for intermediate and long times can be predicted. Comparison with laboratory data from a continuous point source in a simulated atmospheric surface layer is found to be favorable.