标题： 剪切稀化流变学对粘性流体流动中单个刚性椭球粒子的动力学和压力分布的影响 显示英文标题

标题： The Effect of Shear-Thinning Rheology on the Dynamics and Pressure Distribution of a Single Rigid Ellipsoidal Particle in Viscous Fluid Flow

摘要： 本文使用自建的有限元分析（FEA）模拟评估了单个刚性椭球粒子在具有幂律广义牛顿流体（GNF）流变特性的均质粘性流体中的行为。研究了剪切稀化流体流变特性、粒子长宽比、初始粒子取向以及不同均质流场中剪切-拉伸率因子对粒子动力学和表面压力演变的综合影响。发现剪切稀化流体行为会改变粒子的轨迹并改变粒子的运动响应。此外，剪切稀化流体流变特性显著降低了粒子表面的压力分布。通过将牛顿情况的结果与著名杰弗里解析模型的结果进行比较，验证了FEA模型。此外，杰弗里模型被扩展以定义在通常存在于轴对称喷嘴流动收缩中的具有拉伸和剪切速率分量的特殊类均质牛顿流中的粒子轨迹。研究结果提供了对涉及流体-结构相互作用（FSI）的物理过程相关的关键传输现象的更深入理解，例如在纤维增强聚合物复合材料的材料挤出-沉积增材制造过程中形成的流动场中发生的现象。这些结果为打印珠中的重要微观结构形成提供了见解。 显示英文摘要

摘要： This paper evaluates the behavior of a single rigid ellipsoidal particle suspended in homogenous viscous flow with a power-law Generalized Newtonian Fluid (GNF) rheology using a custom-built finite element analysis (FEA) simulation. The combined effects of the shear-thinning fluid rheology, the particle aspect ratio, the initial particle orientation and the shear-extensional rate factor in various homogenous flow regimes on the particle's dynamics and surface pressure evolution are investigated. The shear-thinning fluid behavior was found to modify the particle's trajectory and alter the particle's kinematic response. Moreover, the pressure distribution over the particle's surface is significantly reduced by the shear-thinning fluid rheology. The FEA model is validated by comparing results of the Newtonian case with results obtained from the well-known Jefferys analytical model. Furthermore, Jefferys model is extended to define the particle's trajectory in a special class of homogenous Newtonian flows with combined extension and shear rate components typically found in axisymmetric nozzle flow contractions. The findings provide an improved understanding of key transport phenomenon related to physical processes involving fluid-structure interaction (FSI) such as that which occurs within the flow-field developed during material extrusion-deposition additive manufacturing of fiber reinforced polymeric composites. These results provide insight into important microstructural formations within the print beads.