Kaur Pawandeep, Ganesh Rajaraman
Institute for Plasma Research, HBNI, Bhat, Gandhinagar, 382428, India.
Department of Chemical Physics, Weizmann Institute of Science, 7610001, Rehovot, Israel.
Sci Rep. 2025 Jan 27;15(1):3316. doi: 10.1038/s41598-025-87528-0.
The stability of kinetic-level convection cells (wherein the magnitude of macroscopic and microscopic velocities are of same order) is studied in a two-dimensional Yukawa liquid under the effect of microscopic velocity perturbations. Our numerical experiments demonstrate that for a given system aspect ratio β viz., the ratio of system length [Formula: see text] to its height [Formula: see text] and number of convective rolls initiated [Formula: see text], the fate of the convective cells is decided by [Formula: see text]. For [Formula: see text], Reynolds stress is found to be self-consistently generated and sustained, which results in tilting of convection cells, eventually leading to shear flow generation, whereas for [Formula: see text], parallel shear flow is found to be untenable. An unambiguous quantitative connection between Reynolds stress and the onset of shear flow using particle-level data is established without free parameters. The growth rate of the instability, the role of frictional forces, generalization of our findings and the possibility of realizing the same in experiments are also discussed.
在微观速度扰动的影响下，研究了二维 Yukawa 液体中动力学水平对流元胞（其中宏观和微观速度大小处于同一量级）的稳定性。我们的数值实验表明，对于给定的系统长宽比β，即系统长度[公式：见正文]与其高度[公式：见正文]的比值以及引发的对流卷数量[公式：见正文]，对流元胞的命运由[公式：见正文]决定。对于[公式：见正文]，发现雷诺应力能自洽地产生并维持，这导致对流元胞倾斜，最终导致剪切流的产生，而对于[公式：见正文]，发现平行剪切流是不可持续的。利用颗粒级数据建立了雷诺应力与剪切流起始之间无自由参数的明确定量联系。还讨论了不稳定性的增长率、摩擦力的作用、我们研究结果的推广以及在实验中实现相同情况的可能性。
