发表机构
Okinawa Institute of Science and Technology Graduate University; Shinshu University（冲绳科学技术大学院大学; 信州大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究结合数值模拟与微流控实验，发现粘弹性流体在微柱阵列冠层上方流动时，弹性湍流与弹性波可共存，二者是粘弹性流动的互补表现，为生物和工程环境的运输调控提供了新机制。
AI 中文摘要
粘弹性流体在微织构表面上的流动——这些表面密布着类似呼吸道纤毛或肠道上皮绒毛的细长突起——是运输、混合和吸收等重要生物过程的基础。尽管这类结构普遍存在，但流体弹性与复杂几何结构相互作用产生的动力学仍未被充分探索。本研究结合完全解析的数值模拟与微流控实验，揭示了浸没在粘弹性液体低雷诺数流动中的密集微柱阵列（冠层）上方形成的流动动力学。我们观察到冠层顶端上方的流动会自发发展出弹性湍流，值得注意的是，这种混沌状态与由流体弹性和冠层几何结构诱导的非均匀剪切耦合产生的弹性波共存。这些有序流体运动在广泛的流动条件和冠层构型中持续存在。研究结果表明，相干波传播和弹性湍流是粘弹性流体流动的互补表现形式。除基础意义外，这些机制对生物和工程环境中的运输具有广泛影响，并揭示了结构化几何结构如何利用粘弹性液体的自发动力学来调控复杂流动。
英文摘要
Viscoelastic fluid flows over micro-textured surfaces - densely covered by slender protrusions like cilia lining the body airways or villi covering the intestinal epithelium - underpin essential biological processes including transport, mixing, and absorption. Despite their ubiquity, the dynamics generated by the interplay between fluid elasticity and these complex geometries remain largely unexplored. Here we combine fully resolved numerical simulations with microfluidic experiments to reveal the flow dynamics established above dense arrays of microscopic pillars (canopies) immersed in the low-Reynolds-number flow of a viscoelastic liquid. We observe that the flow above the canopy tips spontaneously develops elastic turbulence. Remarkably, the chaotic state coexists with elastic waves emerging from the coupling between fluid elasticity and the heterogeneous shear induced by the canopy geometry. These ordered fluid motions persist across a broad range of flow conditions and canopy configurations. Our results demonstrate that coherent wave propagation and elastic turbulence are complementary manifestations of viscoelastic fluid flow. Beyond their fundamental significance, these mechanisms have broad implications for transport in biological and engineered environments, and reveal how structured geometries can harness the spontaneous dynamics of viscoelastic liquids to manipulate complex flows.
Comments9+4 pages, 3+2 figures
