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

纤维经常被添加到材料中以提供额外的强度和延长使用寿命。然而，在材料中加入纤维会使加工过程复杂化，因为纤维会在流动过程中改变材料的物理性质。本项目将对刚性棒悬浮液在粘性液体中的流动行为进行实验和计算机模拟。该项目将检查集中悬浮液，其中棒在流动过程中相互作用。此外，该项目将重点关注附近边界墙对悬架结构和物理性能的影响。该项目的结果将为加工纤维材料的工程师提供可用于工艺设计以提高材料性能的信息。该项目将为研究生提供研究培训，为感兴趣的本科生提供研究参与，并通过佛罗里达大学的既定举措加强国际合作。浓缩纤维悬浮液的流变学将在一系列装置中进行实验研究。为了检验约束的影响，器件中边界壁之间的距离将发生变化。附近壁对悬浮液微观结构的影响将通过对棒的成像来确定。由于约束导致的微观结构的变化将与流体流变学的变化相关。实验测量将与周期性边界条件或边界壁的模拟进行比较，以检查微观结构，约束和流变性之间的联系。除了澄清约束的影响外，该项目还将确定控制集中悬浮棒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.