Modeling granular segregation for overlapping species distributions

We explore the segregation of two size-polydisperse particle species with overlapping size distributions using an experimentally validated continuum segregation model and discrete element method simulations. The continuum approach is extended to successfully model segregation for two species with overlapping size distributions. Nevertheless, the impact of species size dispersity on species segregation is weak. Consequently, the local species concentration can be accurately modeled as a mixture of two size-monodisperse species, even if the distributions of the two species overlap. However, the local mean particle size can be influenced by size dispersity in some regions of the flow, particularly for broad size distributions. The segregation length scale, which characterizes the propensity of the two species to segregate, can be measured for mixtures of two polydisperse species as well, and closely follows the value associated with the mean diameters of the two species.