Nonlinear-Flow-Induced Structure in Fiber Suspensions

纤维悬浮液中的非线性流动诱导结构

• 批准号: 9910908
• 负责人: Donald Koch
• 金额: $ 25万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-06-01 至 2004-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9910908&HistoricalAwards=false
• 关键词: Nonlinear; Flow; Induced; Structure; Fiber

AbstractCTS-9910908D. L. Koch, Cornell UniversityThe rheological behavior of such complex fluids as fiber suspensions, crystal polymers, etc. are important in the paper, food, and pharmaceutical industries. Linear solutions exist for a number of these flows, but for many applications, nonlinear terms become important and must be included. It is proposed to study thee nonlinearities in the context of four situations highlighting viscoelasticity, fluid inertia, electrical double layer interactions, and fiber-fiber adhesion:i) Oscillatory linear flows do not show any change of orientation from one cycle to the next: there is, however, a cumulative drift of orientation when non-linear terms appear. Three such cases will be studied for a wide range of amplitude and frequency.ii) The case of fibers suspended in fluids emphasizes the inertia forces when considering their length (high Reynolds numbers), but viscous effects may dominate when the fiber diameter is the relevant dimension (Reynolds numbers near unity). A slender body theory will be developed and applied to the case of a single rotating fiber in a Couette flow.iii) Electrically charged rods are expected to interact with ions of opposite charge, with their resulting effect on the rod orientation. Experiments are planned to test the PI's earlier theoretical work on electoviscous effects.iv) Dense suspensions bring together viscous effects (fluid-body surface interaction) and Columbic friction laws (body-body contact). Such interactions will be studied with special attention to adhesive fiber-fiber contact.

摘要CTS-9910908D。 L. Koch，康奈尔大学纤维悬浮液、晶体聚合物等复杂流体的流变行为在造纸、食品和制药行业中非常重要。 许多此类流都存在线性解，但对于许多应用来说，非线性项变得很重要并且必须包含在内。 建议在强调粘弹性、流体惯性、双电层相互作用和纤维-纤维粘附的四种情况下研究非线性：i) 振荡线性流从一个循环到下一个循环不显示方向的任何变化：有然而，当非线性项出现时，它是方向的累积漂移。 将在大范围的振幅和频率下研究三种这样的情况。ii) 悬浮在流体中的纤维的情况在考虑其长度（高雷诺数）时强调惯性力，但当纤维直径相关时，粘性效应可能占主导地位尺寸（接近统一的雷诺数）。 将开发细长体理论并将其应用于库埃特流中单个旋转纤维的情况。iii) 带电棒预计会与带相反电荷的离子相互作用，从而对棒的方向产生影响。 计划进行实验来测试 PI 早期关于电粘性效应的理论工作。iv) 稠密悬浮液将粘性效应（流体-体表面相互作用）和哥伦摩擦定律（体-体接触）结合在一起。 将研究这种相互作用，特别关注粘合纤维与纤维的接触。