2023 Volume 11 Issue 2 Article ID: 22-15035
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 Sr , bulk volume ratios Vr , 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 Sr and volume ratios Vr; (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 µ0 and solid fraction φ0 in the quasistatic regime, on the system bi-dispersity (i.e., Sr and Vr) is discussed and clarified.