Large eddy simulation of a passive scalar in homogeneous turbulence

The diffusion of a contaminant in a grid turbulence subjected to a constant mean velocity gradient field is studied using large-eddy simulation. The numerical model and the subgrid model are described, and the values of the eddy Prandtl number and the constants of the subgrid model are matched to the heated grid turbulence of Yeh and Van Atta (1973). The diffusion of a spherical source of scalar in grid turbulence subjected to plane strain is considered. Preliminary results are also given for the diffusion of a line source of scalar.