Rheology of Segregated Bi-Disperse Granular Flow in an Inclined Plane

Abstract

This study is an extension based on our previous work 1,2) , in which we mainly discussed the µ(I) rheological model for quasi-monodisperse circular and elliptic systems. In this paper, we numerically study the inclined plane flows composed of two-sized circular particles through the 2D discrete element method. By carrying out simulations with different size ratios S r , bulk volume ratios V r , and slope angles θ (altogether 125 different systems), we discuss how this rheological model works for bi-disperse systems in detail. It is found that (1) the µ(I)-rheology model is still valid for the bi-disperse flows of different size ratios S r and volume ratios V r ; (2) the contact type (large to large, small to small, and large to small particles) proportions are not dependent on the shear rates, which enables us to formulate them for the definition of a generalized inertial number Î; (3) the dependence of fitting parameters, including the mean effective friction coefficients µ 0 and solid fraction φ 0 in the quasistatic regime, on the system bi-dispersity (i.e., S r and V r ) is discussed and clarified.