Li Yunyun, Zhou Yuxin, Marchesoni Fabio, Ghosh Pulak K
Center for Phononics and Thermal Energy Science, Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering, Tongji University, Shanghai 200092, China.
Dipartimento di Fisica, Università di Camerino, I-62032 Camerino, Italy.
Soft Matter. 2022 Jun 29;18(25):4778-4785. doi: 10.1039/d2sm00500j.
We numerically investigated the clustering of a uniform suspension of finite-size disks in a linear array of two-dimensional convection cells. We observed that, due to steric interactions, the disks tend to form coherently rotating spatial structures at the center of each cell, as a combined effect of advection and pair collisions. Micellar, ring-like and hexatic patterns emerge in the deterministic regime, depending on the suspension density, but dissolve in the presence of thermal fluctuations. Moreover, pair collisions suffice to activate cell crossings even by noiseless disks and, therefore, cause athermal diffusion. The robustness of such collision induced effects is studied against the opposing action of thermal noise, transverse biases, and particle self-propulsion.
我们对二维对流单元线性阵列中有限尺寸圆盘均匀悬浮液的聚集进行了数值研究。我们观察到，由于空间相互作用，作为平流和粒子对碰撞的综合效应，圆盘倾向于在每个单元的中心形成相干旋转的空间结构。在确定性状态下，根据悬浮液密度会出现胶束状、环状和六方相图案，但在热涨落存在时会溶解。此外，即使是无噪声的圆盘，粒子对碰撞也足以激活单元穿越，因此会导致无热扩散。针对热噪声、横向偏差和粒子自推进的相反作用，研究了这种碰撞诱导效应的稳健性。
