DENSE GRANULAR FREE-SURFACE FLOWS: COMPARISON BETWEEN <i>μ</i>(<i>I</i>)-RHEOLOGY AND DEM SIMULATION

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

“…3a shows the test of such Bagnold-like scaling as v x = A(θ )(H 3/2 − (H − y)) 3/2 , where the prefactor A(θ ) is a constant term that also increases with θ . This observation agrees with the previous contributions on monodisperse inclined flows 1,3) . As the streamwise velocities are measured, the shear rates can be computed by γ = dv x /dy.…”

“…Among them, a combination of the following expressions is usually adopted to capture the rela-tions in free-surface flows 11,13) . This guarantees the prediction accuracy even without data in low inertial numbers, as reported in our previous work 1) :…”

“…1a, and an incomplete segregation can be observed where many large particles are still buried in the sea of small particles 11,24) . To extract the macroscopic fields of fully developed flows from discrete data, a coarse-graining method 46) is introduced for measurement, which is proved to be valid for obtaining the bulk properties of the flows 1) . The main idea of this approach is that a macroscopic field variable at a certain point (e.g., solid fraction φ , continuum velocity v, and stress tensor σ ), can be obtained by weighting the microscopic variables of particles (e.g., particle mass m i , particle velocity v i , and experienced forces F i ) via a coarsegraining function over space and time.…”

“…named the inertial number 8) , was introduced to normalize the shear strain rate by these quantities and successfully simplified the model as µ(I) and φ (I) relations. The law has been tested for various flow configurations, such as plane shear flow 3,8,10) and rough inclined plane flow 1,3,11) . Many mathematical equations 8,9,12) were proposed to predict the µ(I) and φ (I) relations.…”

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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.

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