Spontaneous violations of the Clausius–Duhem (CD) inequality in Couette-type collisional flows of model granular media are studied. Planar systems of monosized circular discs (with disc numbers from 10 to 204, and disc diameters from 0.001 m to 1 m) with frictional-Hookean contacts are simulated under periodic boundary conditions by a molecular dynamics. The scale-dependent homogenization of micropolar media is used to determine the energy balances and mechanical entropy production. The dissipation function exhibits spontaneous negative entropy increments described by the fluctuation theorem. The boundary between violations and non-violations of the CD inequality is mapped in the parameter space, where the probability of such events diminishes with the disc diameter, the disc number and the area fraction increasing. The dissipation function is a random process, tending to Gaussian as the number of discs increases, and possessing non-trivial fractal and anti-persistent Hurst properties.

中文翻译：

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颗粒介质 Couette 流中 Clausius-Duhem 不等式的违反

研究了模型颗粒介质的 Couette 型碰撞流中 Clausius-Duhem (CD) 不等式的自发违反。通过分子动力学在周期性边界条件下模拟具有摩擦-胡克接触的单尺寸圆盘（盘数从 10 到 204，盘直径从 0.001 m 到 1 m）的平面系统。微极介质的尺度相关均质化用于确定能量平衡和机械熵产生。耗散函数表现出由涨落定理描述的自发负熵增量。CD 不等式的违反和非违反之间的边界映射在参数空间中，其中此类事件的概率随着圆盘直径、圆盘数量和面积分数的增加而减小。