Large eddy simulation of the dispersion of solid particles and droplets in a turbulent boundary layer flow.

VINKOVIC, I., C. A. AGUIRRE AND S. SIMOËNS

Serdeña

Simposio; International Simposium on Engineering Turbulence Modelling and Experiments; 2005

European Research Community on Flow, Turbulence and Combustion (ERCOFTAC)

In order to study the dispersion of droplets and solid particles in neutral atmospheric surface layers a large eddy simulation (LES) using the dynamic sub-grid scale model of Germano, was coupled with a Lagrangian stochastic model for particle trajectories. The flow dynamics are computed with a LES. The droplets are tacked by solving the modified version of the BBO equation of motion for a small rigid sphere in a turbulent flow. In order to take into account the subgrid-scale (SGS) motion of particles, the velocity of the fluid encountered by the particle is computed with two components. Namely, to the large scale velocity directly computed by the LES we added a fluctuation value obtained by a one particle, one time-scale Lagrangian stochastic model. A final coalescence/breakup model is used to take into account the interactions of droplets. Tracking droplets with a LES coupled with a stochastic model allows the computation of SGS fluctuations which are essential for inter-particle interactions and chemical reactions. The specificities of this study reside in the use of a LES coupled with a stochastic model for the study of the dispersion of solid particles and droplets.