AI 中文总结
研究活性手性薄膜中奇响应的产生，基于经典剪切流变学，用动力学理论从微观推导其应力响应，揭示相关机制，数值解突出强剪切下的特征，确立活性手性薄膜为奇流体动力学新可控环境。
AI 中文摘要
活性手性流体可支持一种称为奇（或霍尔）粘度的无耗散输运系数。对此类流体的流体动力学描述通常凭经验引入奇粘度。这种响应如何从特定微观相互作用中产生仍未完全理解。在此，基于经典剪切流变学，我们从微观角度推导了活性手性薄膜中的奇流变响应。利用动力学理论推导其应力响应，揭示剪切诱导的重新定向导致流动对齐极化和横向表面牵引力，由此奇粘度张量以封闭形式得出。非线性动力学理论的数值解进一步突出了强剪切下横向牵引力的饱和。结果表明奇粘度可作为活性流体 - 结构相互作用的粗粒化流变特征自洽出现，并将活性手性薄膜确立为奇流体动力学的新可控环境。
英文摘要
Active chiral fluids can support a nondissipative transport coefficient known as odd (or Hall) viscosity. Hydrodynamic descriptions of such fluids typically introduce odd viscosity phenomenologically. How such a response emerges from specific microscopic interactions remains incompletely understood. Here, building on classical shear rheology, we microscopically derive an odd rheological response in active chiral films: thin layers of torque-exerting, elongated particles anchored to a no-slip surface. A canonical realization of such a film is the bacterial carpet, in which flagellated bacteria are tethered head-down to a solid surface while their flagella remain free to spin and inject angular momentum into the surrounding fluid. Using a kinetic theory for the orientational dynamics of these anchored particles, we derive their stress response to an imposed shear flow. We reveal that shear-induced reorientation leads to a flow-aligned polarization and a transverse surface traction from which the odd-viscosity tensor follows in closed form. Numerical solutions of the nonlinear kinetic theory further highlight saturation of the transverse traction at strong shear, driven by shear-induced orientation dynamics -- signaling departure from linear response. Our results demonstrate how odd viscosity can emerge self-consistently as a coarse-grained rheological signature of active fluid-structure interaction and establish active chiral films as a new controllable setting for odd hydrodynamics.
