Turbulent Diffusion Mechanism in the Modelled Turbulence Field and Its Application

Turbulent diffusion mechanism in the modelled turbulence field is considered by using the relation between Lagrangian correlation coefficient and Eulerian space-time correlation one proposed by Corrsin. As the results, the longitudinal turbulent diffusion coefficient is related to the transverse one in terms of the ratio of the turbulent intensities of each direction. The result is applied to the estimation of the distribution of diffusion coefficient in open channel flows with the Eulerian turbulent characteristics calculated by using the turbulence model in this paper.