The purpose of this paper is to present the methodology and preliminary results of a coupled approach between a stochastic lagrangian approach and a two-fluid method in gas-particle turbulent flows. The study is limited to the case of inert monodispersed particle flows without two-way coupling. Thus the particles only experience drag and gravity as external forces. However, particle-particle interactions (i.e. collisions) are taken into account. The dispersed phase is represented in terms of a joint fluid-particle probability density function (pdf) which obeys a Boltzmann-like equation. This evolution equation is then solved using two different approaches, depending on the location in the flow. The first one is a stochastic lagrangian approach which embeds a Langevin equation for the fluid velocity seen along the particle path and a Monte-Carlo collision algorithm simulating particle-particle interactions. The second one is a second-order momentum approach derived from the preceding stochastic lagrangian approach. Turbulent dispersion and collision terms are modeled following Simonin [1]. These two approaches are then to be coupled. The coupling is carried through half-fluxes, allowing well-posed boundary conditions stemmed from previous time-step statistics.
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