Statistical analysis of the anisotropy of scalar diffusion in turbulent shear flows

Abstract

Anisotropy of the diffusion of a passive scalar is studied statistically by means of the direct-interaction approximation incorporated with the multiscale expansion method. The scalar flux generated by turbulent shear flows is calculated up to the second order of a scale parameter. As a result, a relation between the anisotropy of scalar diffusion and the inhomogeneity of turbulent flows is shown. © 1985 American Institute of Physics.