UNS: Dynamics and Rheology of Concentrated Suspensions of Rigid Rods: Effects of Confinement

CBET-1511787PI：Jason Butler纤维通常被添加到材料中以提供额外的强度和延长寿命。然而，将纤维添加到材料中会使加工变得复杂，因为纤维会在流动过程中导致材料的物理属性发生变化。该项目将对粘性液体中刚性杆悬浮液的流动行为进行实验和计算机模拟。该项目将研究浓缩悬浮物，在这些悬浮物中，棒在流动期间相互作用。此外，该项目将重点研究附近的围墙对悬挂的结构和物理性能的影响。该项目的结果将提供信息，供加工纤维材料的工程师在工艺设计中使用，以提高材料的性能。该项目将为研究生提供研究培训，为感兴趣的本科生提供参与研究的机会，并通过在佛罗里达大学建立的倡议加强国际合作。浓缩纤维悬浮液的流变性将在一系列设备中进行实验研究。为了检查限制的影响，设备中的边界墙之间的距离将有所不同。附近墙壁对悬浮液微观结构的影响将通过对棒进行成像来确定。由于约束引起的微观结构的变化将与流体流变性的变化相关。实验测量将与周期性边界条件或边界墙的模拟进行比较，以检查微观结构、约束和流变学之间的联系。除了阐明约束的影响外，该项目还将确定控制浓缩棒悬浮物结构和动力学的物理机制。

CBET - 1511787PI: Jason ButlerFibers often are added to materials to provide extra strength and improve lifetime. However, adding fibers to a material complicates processing, because the fibers cause changes in the physical properties of the material during flow. This project will conduct experiments and computer simulations of the flow behavior of suspensions of rigid rods in a viscous liquid. The project will examine concentrated suspensions where the rods interact with each other during flow. Furthermore, the project will focus on the effects of nearby bounding walls on the structure and physical properties of the suspension. Results of the project will provide information that engineers who process fibrous materials can use in process design to enhance material properties. The project will provide research training for graduate students, research involvement for interested undergraduates, and opportunities to enhance international collaborations through established initiatives at the University of Florida.The rheology of concentrated fiber suspensions will be studied experimentally in a series of devices. To examine effects of confinement, the distance between bounding walls in the devices will be varied. The effects of nearby walls on the microstructure of the suspension will be determined by imaging the rods. Changes in the microstructure due to confinement will be correlated with changes in fluid rheology. Experimental measurements will be compared to simulations with periodic boundary condition or with bounding walls to examine connections between microstructure, confinement, and rheology. In addition to clarifying the influence of confinement, the project will identify the physical mechanisms that control structure and dynamics of concentrated suspensions of rods.