Analyzing effects of microscopic material parameters on macroscopic mechanical responses in underwater mixing using discrete element method
Analyzing effects of microscopic material parameters on macroscopic mechanical responses in underwater mixing using discrete element method
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DOI：
10.1016/j.powtec.2022.117304
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发表时间：
2022-03
影响因子：
5.2
通讯作者：
Jian Chen-;A. Kitamura;E. Barbieri;D. Nishiura;M. Furuichi
中科院分区：
文献类型：
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作者：
Jian Chen-;A. Kitamura;E. Barbieri;D. Nishiura;M. Furuichi
混合工艺在许多工业领域中通常用于处理粉末和颗粒，并且其性能已经受到广泛的研究。然而，在新的深海采矿应用中，对水下混合的研究有限。因此，我们采用离散元法（DEM）的润滑模型增强水下混合过程的研究。本文主要研究材料的微观参数对宏观力学响应的影响。DEM样品的初始密度控制良好，宏观响应的变化很小，最大的变异系数（CV）小于1.4%，在侧壁上的归一化力，CV值小于1.0%，其他宏观响应。进行了全面的参数研究的弹性模量和耗散参数。弹性模量表现出可以忽略不计的影响，和耗散参数的影响范围从最显着的滚动摩擦系数，摩擦系数，恢复系数，和流体粘度的顺序最可以忽略不计。我们进一步讨论了力链和剪切引起的尺寸偏析的网络连接，发现滚动摩擦的增加增加了主应力链中颗粒的连接性，从而增加了混合阻力。尺寸偏析监测DEM样品的颗粒，最初遵循一个均匀的尺寸分布：摩擦的增加，观察到提高隔离和流体粘度的增加，以减轻it.The本文的研究结果可以推进水下混合的动力学的理解，并提供见解设计混合系统的粒状材料与材料性能的大变化。
Mixing processes are commonly used to handle powders and grains in several industrial fields, and their performance has been subjected to extensive study. However, research is limited on underwater mixing in novel deep-sea mining applications. Consequently, we adopt a discrete element method (DEM) enhanced by a lubrication model to investigate the underwater mixing process. We focus on the effect of microscopic material parameters on macroscopic mechanical responses in this study. Variations in macroscopic responses are small among DEM samples with a well-controlled initial density; the largest coefficient of variation (cv) is less than 1.4% in normalized forces on the sidewall, and the values of cv are less than 1.0% for other macroscopic responses. A comprehensive parametric study is conducted for elastic moduli and for dissipative parameters. Elastic moduli exhibited a negligible influence, and the effects of dissipative parameters ranged from most significant to most negligible in the order of coefficient of rolling friction, coefficient of friction, coefficient of restitution, and fluid viscosity. We further discuss the network connectivity of force chains and shear-induced size segregation; it was found that an increase in rolling friction increases the connectivity of particles in principal stress chains, which increases the mixing resistance. Size segregation is monitored for DEM samples with particles that initially follow a uniform size distribution: an increase in friction is observed to enhance the segregation and an increase in fluid viscosity to alleviate it. The findings in this paper can advance the understanding of the dynamics of underwater mixing and offer insights for designing mixing systems for granular materials with large variations in material properties.