Time-dependent density segregation of binary granular mixtures flowing over a periodic chute*

We study time-dependent density segregation of binary granular mixtures flowing over an inclined plane. Discrete Element Method (DEM) simulations in a periodic box are performed for mixtures having an identical size and different density particles flowing under the influence of gravity. The particle force-based density segregation theory (Tripathi and Khakhar, J. Fluid Mech., 717:643–669, 2013) has been used to predict time-dependent segregation by accounting for the inter-coupling of segregation with rheology. A two-way coupled continuum model is developed to solve the momentum balance equations along with particle force-based segregation transport equation and mixture rheology using Matlab PDEPE solver. Various flow properties of interest such as species concentration, velocity, pressure and shear stress at different times steps are compared with DEM results. The time-dependent evolution of flow properties from the continuum model is found to be in good agreement with the DEM simulations for different density ratios of heavy to light particles over a wide range of compositions at different inclination angles.

References:

[1]  Anurag Tripathi and D. V. Khakhar. “Density difference-driven segregation in a dense granular flow”. J. Fluid Mech., 717:643–669, 2013.