The Role of Friction in Mixing and Segregation of Granular Material
نویسندگان
چکیده
The process of size segregation in a model system of granular matter, consisting of 1600 spherical poly-disperse particles stirred by a rectangular bar moving periodically in the horizontal direction, was modelled by the discrete element method under different values of dynamic friction coefficient of the particle material. It has been shown that the dynamic friction coefficient influences the processes of mixing and size segregation in polydisperse granular systems. The equation was proposed that characterizes the evolution of segregation intensity approaching exponentially a certain steady state value. The dependence of the rate of segregation intensity upon dynamic friction coefficient is nonmonotonous: the rate of segregation intensity is higher at lower values of the dynamic friction coefficient and attains a minimum value as the dynamic friction coefficient increases up to μcrit ~ 0.1, but starts to increase again for the higher values of the dynamic friction coefficient. This dependence indicates the presence of competing segregation mechanisms, one of which dominates at the given experimental conditions and material properties. The intensity of particle mixing demonstrates similar dependency on the dynamic friction coefficient.
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