论文标题
建模流动bidisperse颗粒混合物的隔离，大小和密度同时变化
Modelling segregation of flowing bidisperse granular mixtures varying simultaneously in size and density
论文作者
论文摘要
由于粒度差异（由渗透率驱动）和密度（由浮力驱动），流动的颗粒材料分离。由于两种隔离机制的相反作用，大/重颗粒和小/光颗粒的混合物的隔离建模是具有挑战性的。使用离散元素方法（DEM）组合尺寸和密度隔离的模拟，我们表明隔离速度是通过线性依赖局部剪切速率并四次地依次依赖物种浓度的模型来很好地描述的。通过将这种隔离速度模型纳入连续的对流扩散 - 分离模型匹配DEM仿真结果的浓度曲线通过将粒径和密度比的范围很好地匹配。最令人惊讶的是，DEM模拟和隔离速度模型都表明，大小和密度比的隔离方向取决于局部物种的浓度。这导致了一种方法，以确定粒度比，密度比和颗粒浓度的组合，而二散混合物不会分离。
Flowing granular materials segregate due to differences in particle size (driven by percolation) and density (driven by buoyancy). Modelling the segregation of mixtures of large/heavy particles and small/light particles is challenging due to the opposing effects of the two segregation mechanisms. Using discrete element method (DEM) simulations of combined size and density segregation we show that the segregation velocity is well described by a model that depends linearly on the local shear rate and quadratically on the species concentration. Concentration profiles predicted by incorporating this segregation velocity model into a continuum advection-diffusion-segregation transport model match DEM simulation results well for a wide range of particle size and density ratios. Most surprisingly, the DEM simulations and the segregation velocity model both show that the segregation direction for a range of size and density ratios depends on the local species concentration. This leads to a methodology to determine the combination of particle size ratio, density ratio, and particle concentration for which a bidisperse mixture will not segregate.
