对颗粒物质运动的一致性进行控制的随机力场

在颗粒流的研究中引入了一个正态分布的随机力场, 并通过计算机模拟研究了该力场对均匀颗粒流的影响. 结果发现: 随机力场基本上不改变均匀颗粒流的平均密度和速度, 对颗粒流密度的涨落也影响很小. 随机力场对均匀颗粒流的影响主要体现在它可提高速度的涨落, 它与颗粒体系的耗散性质相抗衡, 使颗粒流维持一定的波动能量. 研究结果还显示: 通过随机力场所获得的波动能量并没有均匀分布到各个自由度上, 由于颗粒体系的耗散性质颗粒体系难以达到能均分状态.关键词：颗粒物质随机力分子动力学模拟

Control of the fluctuation in the uniform granular flow by a random force field*

A normal distribution random force field is introduced into the study of granular flow, and its effect is observed by computer simulations. The results show that the random force almost does not cause changes in average density and velocity in a uniform granular flow, and affects little the fluctuation of the density. The main effect of the random force field is that it increases the fluctuation of the granular velocity and maintains the granular flow at a certain dispersed kinetic energy by competing with the dissipation of the granular system. It is also shown that the dispersed kinetic energy obtained by the random force field is not equally distributed in each degree of freedom, and that the equipartition of energy is difficult to realize in granular system because of its dissipation property.
Keywords：granular matterrandom forcemolecular dynamics simulation