CAREER: Suspensions of Noncolloidal Particles in Yield Stress Fluids: Fluid Mechanics, Rheology and Microstructure

CBET - 1554044PI：Hormozi，SarahSlurries 是粘性液体中颗粒的浓缩悬浮液。它们存在于自然环境中，例如山体滑坡、泥石流和水下雪崩，也存在于工业环境中，例如采矿作业的尾矿中。 该职业项目的目标是开发实验和建模方法，以检查当输送颗粒的粘性液体本身表现出复杂行为时浆料的流体动力学行为。 实验将涵盖广泛的流动状态，其结果将填补了解浆料流动特性的重要知识空白。 这种理解对于准确预测自然灾害如何发生和蔓延以及避免或减少其影响至关重要。 该项目中获得的数据对于有兴趣开发新浆料模型的研究人员以及开发处理这些复杂材料的设备的从业人员来说非常有用。 此外，该项目的结果将被纳入俄亥俄大学的课程中。从事该项目的研究人员将参加各种外展项目，包括 TechSavvy、为女孩和支持她们的成年人举办的职业会议，以及为高中女生举办的住宿技术营，为年轻女性提供探索工程和技术职业的机会。该职业项目的重点是开发实验和建模技术，以研究浆料的流变特性，其中悬浮液体本身表现出非牛顿行为，包括屈服应力和剪切稀化。 例如，尾矿和残渣就是这种情况，其中小的胶体颗粒赋予悬浮液体非牛顿行为，从而影响较大的非胶体颗粒悬浮液的流变性。 实验将跨越低雷诺数到惯性状态，并将确定颗粒压力张量和剪切引起的颗粒迁移动力学。 射线照相和三维显微断层扫描将用于确定颗粒的局部体积分数和局部应力分量。 颗粒成像和跟踪测速将用于表征底层的微观结构，即颗粒的空间和时间排列，并将其与浆料的宏观流变学联系起来。 研究结果将用于开发准确的理论框架来模拟地球物理流并预测起始、扩散动力学和跳动，这将有助于限制自然灾害的影响。

CBET - 1554044PI: Hormozi, SarahSlurries are concentrated suspensions of particles in a viscous liquid. They are found in natural settings, such as landslides, mudslides, and underwater avalanches, and in industrial settings, such as in tailings from mining operations. The goal of this CAREER project is to develop experimental and modeling methods to examine the fluid dynamical behavior of slurries when the viscous liquid that conveys the particles exhibits complex behavior on its own. The experiments will cover a wide range of flow regimes, and the results will fill an important knowledge gap in understanding the flow characteristics of slurries. This understanding is essential to make accurate predictions of how natural disasters start and spread and to avoid or reduce their impacts. Data acquired in the project will be useful to researchers who are interested in developing new models of slurries and to practitioners who develop equipment to process these complex materials. In addition, results from the project will be incorporated into classes at Ohio University. Researchers working on the project will participate in a variety of outreach programs, including TechSavvy, a career conference for girls and the adults who support them, and a residential Technology Camp for high school girls that provides opportunities for young women to explore careers in engineering and technology.This CAREER project focuses on the development of experimental and modeling techniques to investigate rheological properties of slurries in which the suspending liquid by itself exhibits non-Newtonian behavior, including a yield stress and shear-thinning. For example, this is the case in mine tailings and debris, where small colloidal particles impart non-Newtonian behavior to the suspending liquid that affects the rheology of suspensions of larger, noncolloidal particles. The experiments will span low-Reynolds number to inertial regimes, and will determine the particle pressure tensor and the kinetics of shear-induced migration of the particles. Radiography and three-dimensional micro-tomography will be used to determine the local volume fraction of the particles and the local stress components. Particle imaging and tracking velocimetry will be used to characterize the underlying microstructure, i.e., the spatial and temporal arrangement of the particles, and connect it to the macroscopic rheology of the slurry. Results will be used to develop accurate theoretical frameworks to model geophysical flows and predict initiation, spreading dynamics and runout, which will help limit the impact of natural disasters.