The purpose of this thesis is to analyse the results of numerical computations of polydispersed turbulent two-phase flows using a LES/VFDF approach. In this approach, the numerical solution is obtained by resorting to a hybrid method, where the fluid properties are computed by solving filtered-field (LES) equations whereas the local instantaneous properties of the particles are determined by solving stochastic differential equations (SDEs). The fundamentals of the general formalism are recalled in the first part, while the second part is focused on the work of implementation of the stochastic module and on the tests of consistency carried out to validate the code. Finally some results are shown for particle preferential concentration in a turbulent channel