Implementation of Defiltering Techniques in Large-eddy Simulation of Particle-laden Turbulent Flows

In most studies of particle-laden turbulent flows in which the carrier phase is simulated by LES and particles are individually tracked in the Lagrangian framework, the effect of sub-filter scales on particles is neglected. However, the error resulted from such neglect can be significant if the sub-filter energy is relatively large and/or particle time constant is small. It has been recently shown that the prediction of turbuphoresis in the wall-bounded turbulence (Kuerten {\&} Vreman, \textit{Phys. Fluids} \textbf{17}, 017011, 2005) and particle dispersion in the homogeneous turbulence (Shotorban {\&} Mashayek, \textit{Phys. Fluids }\textbf{17}, 081701, 2005) can be largely improved if the sub-filter scales are reconstructed for particles via defiltering. In this work, the formulation for the use of defiltering techniques in the LES of particle-laden turbulent flows is reviewed and recent results obtained for the particle-laden homogeneous isotropic and shear flows are presented.