Noirhomme M, Opsomer E, Vandewalle N
GRASP, Institute of Physics B5a, <a href="https://ror.org/00afp2z80">University of Liège</a>, B4000 Liège, Belgium.
Phys Rev E. 2024 Nov;110(5-1):054901. doi: 10.1103/PhysRevE.110.054901.
Granular fluids, as defined by a collection of moving solid particles, is a paradigm of a dissipative system out of equilibrium. Inelastic collisions between particles is the source of dissipation, and is the origin of a transition from a gas to a liquidlike state. This transition can be triggered by an increase of the solid fraction. Moreover, in compartmentalized systems, this condensation is driving the entire granular fluid into a Maxwell demon phenomenon, localizing most of the grains into a specific compartment. Classical approaches fail to capture these phenomena, thus motivating many experimental and numerical works. Herein, we demonstrate that the Onsager variational principle is able to predict accurately the coexistence of gas-liquid states in granular systems, opening ways to model other phenomena observed in such dissipative systems like segregation or the jamming transition.
由移动的固体颗粒集合所定义的颗粒流体，是一种非平衡耗散系统的范例。颗粒之间的非弹性碰撞是耗散的来源，也是从气态转变为类液态的起源。这种转变可以由固体分数的增加引发。此外，在分隔系统中，这种凝聚正在将整个颗粒流体驱动到麦克斯韦妖现象中，使大多数颗粒定位到特定的隔室中。经典方法无法捕捉这些现象，因此激发了许多实验和数值研究工作。在此，我们证明昂萨格变分原理能够准确预测颗粒系统中气液状态的共存，为模拟在这种耗散系统中观察到的其他现象（如分离或堵塞转变）开辟了道路。
