Forced segregation in binary granular mixtures

Mixing granular particles of dierent sizes is a common way of increasing the packing fraction. Recently, a model predicting the packing fraction, taking into account the inhomogeneity of the mixed small and large particles, has been proposed by S. Pillitteri et al. Under certain conditions, this model can be simplied and analytical solutions can be found. We present here these solutions, compared to experimental data, and the physical interpretation they can bring.