Suspension Dynamics with Inertia: Combined Discrete-Particle Simulation and Constitutive Modeling Investigations

惯性悬架动力学：离散粒子模拟与本构建模研究相结合

• 批准号: 0853720
• 负责人: Jeffrey Morris
• 金额: $ 30万
• 依托单位: CUNY City College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-04-01 至 2014-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0853720&HistoricalAwards=false
• 关键词: Suspension; Dynamics; Inertia; Combined; Discrete

0853720MorrisThis project addresses flow of suspensions of rigid particles with inertia at the particle scale. Inertia on the particle scale is defined in terms of the Reynolds number based on shear rate, particle radius and kinematic viscosity. Significant particle-scale inertia implies Reynolds number greater than unity. For small particles, this usually implies larger inertia at the macroscopic scale. Consequently, inertial behavior on multiple scales must be considered. Based on the PI's prior simulations verified against experiment and established simulations, the focus of this study is on simulation of particle-laden flows at finite Reynolds numbers, exploring motions of individual particles as well as particle suspensions. The simulations use the PI's recent developments in the lattice-Boltzmann technique, implemented in a parallel computational algorithm. A number of basic flows will be simulated, including periodic simple shear and pressure-driven flow in conduits, all under a range of finite-Reynolds number conditions with varying particle volume fraction. Flow through conduits showing migrations leading to pronounced accumulation at certain locations have been previously observed. Determination of effective properties of suspensions and modeling of their bulk flow is essential to engineering application of these mixtures. Using statistical analysis of the stress and hydrodynamic diffusivity, a continuum model for suspension flow will be developed. Model predictions will be compared against more complex flows, both from simulations and from experiments. The investigation of bulk suspensions is basic to a wide range of applications involving such materials as inks, coatings and cement as well as many naturally occurring flows. By developing discrete-particle understanding which may be used by theorists and modelers, and developing a continuum description directly from the results, this investigation provides guidance and direction on two fronts. Suspension dynamics is a complex topic, involving physics, mathematics and engineering and thus provides excellent training ground for doctoral and undergraduate research students. The project is designed to involve graduate and undergraduate researchers at one of the most diverse research university settings in the world, the City College of New York. Through collaborations with different universities, laboratories, and industries, young researchers will gain exposure to disciplines from biomedical diagnostics (cell sorting) to the delivery of ceramic precursors and cement. The research results will aid in developing a module in an introductory course using hydrodynamic effects for sorting in microfluidic devices.

0853720Morris该项目解决了颗粒尺度上具有惯性的刚性颗粒悬浮液的流动。颗粒尺度上的惯性是根据基于剪切速率、颗粒半径和运动粘度的雷诺数来定义的。显着的粒子尺度惯性意味着雷诺数大于1。对于小颗粒，这通常意味着宏观尺度上更大的惯性。因此，必须考虑多个尺度的惯性行为。基于 PI 先前通过实验验证的模拟和已建立的模拟，本研究的重点是模拟有限雷诺数下的颗粒负载流，探索单个颗粒以及颗粒悬浮液的运动。模拟使用了 PI 在格子玻尔兹曼技术方面的最新进展，并以并行计算算法实现。将模拟许多基本流动，包括管道中的周期性简单剪切和压力驱动流动，所有这些都在具有不同颗粒体积分数的有限雷诺数条件下进行。先前已观察到流经管道的流动显示出迁移导致某些位置出现明显的积累。确定悬浮液的有效特性并对其整体流动进行建模对于这些混合物的工程应用至关重要。通过对应力和流体动力学扩散率的统计分析，将开发悬浮液流动的连续介质模型。模型预测将与来自模拟和实验的更复杂的流程进行比较。散装悬浮液的研究是涉及油墨、涂料和水泥等材料以及许多自然发生的流动的广泛应用的基础。 通过发展理论家和建模者可以使用的离散粒子理解，并直接从结果中发展连续描述，这项研究在两个方面提供了指导和方向。悬浮动力学是一个复杂的课题，涉及物理、数学和工程学，因此为博士生和本科生研究生提供了良好的训练基础。该项目旨在吸引世界上最多元化的研究型大学之一——纽约城市学院的研究生和本科生研究人员参与。通过与不同大学、实验室和行业的合作，年轻的研究人员将接触到从生物医学诊断（细胞分选）到陶瓷前体和水泥的输送等学科。研究结果将有助于在入门课程中开发一个模块，利用流体动力学效应在微流体装置中进行分类。