arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1608.01757physics.flu-dyncond-mat.soft
收藏

剪切活性流体中的几何相关粘度降低

Geometry-dependent viscosity reduction in sheared active fluids

Jonasz Słomka, Jörn Dunkel

摘要:

我们研究流动斑图形成和粘度降低机制的活性流体通过研究广义Navier-Stokes模型,捕捉实验观察到的大量的涡旋动力学在微生物悬浮液。我们提出了精确的解析解,包括无应力涡格,并引入了一个计算框架,允许有效地处理以前棘手的高阶剪切边界条件。大规模的参数扫描确定自发流动对称性破缺,几何形状相关的粘度降低和负粘度状态服从于能量收集在受限的悬浮液的条件。该理论只使用一般假设的对称性和长波长结构的主动应力张量,这表明,无粘相可以实现在一个广泛的类的非平衡流体通过调整限制几何形状和图案尺度的选择。

英文摘要:

We investigate flow pattern formation and viscosity reduction mechanisms in active fluids by studying a generalized Navier-Stokes model that captures the experimentally observed bulk vortex dynamics in microbial suspensions. We present exact analytical solutions including stress-free vortex lattices and introduce a computational framework that allows the efficient treatment of previously intractable higher-order shear boundary conditions. Large-scale parameter scans identify the conditions for spontaneous flow symmetry breaking, geometry-dependent viscosity reduction and negative-viscosity states amenable to energy harvesting in confined suspensions. The theory uses only generic assumptions about the symmetries and long-wavelength structure of active stress tensors, suggesting that inviscid phases may be achievable in a broad class of non-equilibrium fluids by tuning confinement geometry and pattern scale selection.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑