Vargas Watson L, McCarthy J J
Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2007 Oct;76(4 Pt 1):041301. doi: 10.1103/PhysRevE.76.041301. Epub 2007 Oct 16.
In this paper, we report results and analysis on a simulation study of the effects of thermal expansion in granular systems. We show that these effects impact the force distribution inside a two-dimensional system of disks that are subject to thermal heating under two different boundary conditions. A significant increase in the average force is observed for steel particles confined within a box with fixed walls at temperature rises of 50 degrees C and 100 degrees C, respectively. As previously noted in the literature, thermal expansion also induces compaction. The results show that a systematic and controllable increase in granular packing can be induced by simply raising and then lowering the temperature, without the input of mechanical energy in agreement with previous experimental observations. We find that the evolution of the packing fraction is well described by a fractional relaxation model, which follows the Mittag-Leffler law.
在本文中，我们报告了关于颗粒系统热膨胀效应模拟研究的结果与分析。我们表明，这些效应会影响二维圆盘系统内部的力分布，该系统在两种不同边界条件下受热。对于分别在温度升高50摄氏度和100摄氏度时被限制在具有固定壁的盒子内的钢颗粒，观察到平均力有显著增加。如文献中先前所述，热膨胀还会引发压实。结果表明，通过简单地升高然后降低温度，在不输入机械能的情况下，可以诱导颗粒堆积有系统且可控地增加，这与先前的实验观察结果一致。我们发现，堆积分数的演化可以用遵循米塔格 - 莱夫勒定律的分数弛豫模型很好地描述。
