利用受驱胶体粒子调控活性液晶动力学
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摘要：
利用数值模拟研究了受驱转动的胶体粒子对活性液晶动力学的调控作用。基于数值模拟软件Open-FOAM的overset动态网格框架，构建了由活性液晶与受驱胶体粒子组成的流固耦合模型，分析了不同束缚条件下通过胶体粒子施加的外驱动力对活性流场的影响。在强受限系统中，极小的驱动力即可引导活性流体的对称性破缺，实现活性流场方向的动态、实时调控;在中等束缚下，受驱胶体可破坏活性流体自组织形成的复杂流场结构，诱导产生有序的单向流;在弱受限活性湍流态中，胶体粒子仍可驱动流体，但受活性湍流影响，其驱动范围仅限于活性尺度范围内。此外，还利用此系统测量了活性流体的有效黏滞系数，发现有效黏性随活性增强而降低，且受活性液晶的流对齐参数影响.该研究为活性流体动力学的调控提供了新思路，在微流控技术和生物医学等领域具有潜在应用价值。
We study the dynamics of active nematics controlled by colloidal particles with external driving. Basing on the overset dynamic mesh technique provided by the OpenFOAM package, we develop a solid-fluid interaction model. We analyze the effects of driven colloids on the active flow fields at different degrees of confinement. In strongly-confined systems, a small driving on the colloid can guide the symmetry breaking of active nematics, allowing us to control the direction of active flow dy-namically. At medium confinement. the driven colloid can disrupt the selF-organized structured coherent flow. and promote a simpler uni-directional flow whose direction coincides with that of the external driving. In the case of minimal conlinement, the active nematies exhibits active turbulent fow. In this case, the colloid has limited eflects on the flow field due to the inberent chaotic dynamics. Finally, we also take advantage of this seting to measure the effective viscosity of the active nematics, which decreases with the activity and shows strong dependence on the flow alignment parameter. Our results shed new light on the control of dynamics of active fluids, which can potentially benefit fields such as microfluidics and biomedicine.
作者:
郭子晗，游智
Guo Zihan,You Zhihong
机构地区：
厦门大学物理科学与技术学院
引用本文：
郭子晗,游智鸿.利用受驱胶体粒子调控活性液晶动力学[J].河南师范大学学报(自然科学版),2026.54(2):46-52.(Guo Zihan, You Zhihong. Controlling the dynamics of active nematics with driven colloidal particles[J].Journal of Henan Normal University(Natural Science Edition).2026, 54(2):46-52.DOI:10.16366/j.cnki.1000-2367.2025.04.02.0001.)
基金：
国家自然科学基金
关键词：
活性液晶；胶体；自组织；流场调控；流变
active nematics; colloids; self-organization; flow control;rheology
分类号：
O469
