Dispersion of fluid particles in non-homogeneous turbulence was studied for fully
developed flow in a channel. A point source at a distance of 40 wall units from the
wall is considered. Data obtained by carrying out experiments in a direct numerical
simulation (DNS) are used to test a stochastic model which utilized a modified
Langevin equation. All of the parameters, with the exception of the time scales, are
obtained from Eulerian statistics. Good agreement is obtained by making simple
assumptions about the spatial variation of the time scales.