SGER: Accumulation of Particulates in Complex Flows: Characterization by NMR Imaging

摘要CTS-0425187N。这项研究的任务是探索与工业和生物系统相关的复杂流动中分散颗粒(颗粒或液滴)的行为。在制药、食品、石油和塑料行业的许多过程中，都可以发现集中分散液(含有许多离散颗粒或液滴的液体)的流动，但它们的行为很难控制，这通常是由于持续相互作用的颗粒或液滴的不均匀分布。这项研究的学术价值来自于对复杂流动几何形状和随时间变化的流动中颗粒分布进行量化的目标。在复杂的流动中(既有剪切又有伸长)，现有的浓缩悬浮液连续介质模型往往不能预测观察到的颗粒分布，复杂几何结构的数值模拟过于繁重，计算不切实际，实验数据稀少。我们的目标是在简化的模型系统中获取对浓缩悬浮液和乳状液的精确测量，以捕捉真实循环、生物反应器或制造过程的关键要素。我们将应用非侵入性核磁共振成像(NMRI)和光学方法来量化这些系统中的浓度和速度分布，并将观测与颗粒特性联系起来。NMRI用于不透明系统以及体外和体内的巨大能力，开辟了光学技术无法达到的系统的全新维度。本研究将解决的复杂流动的目标要素是扰动流动中的颗粒积累。我们的目标是确定决定颗粒累积的最重要的系统参数，并量化颗粒浓度和速度分布作为测试连续介质模型预测的基准。这项研究有望揭示弥散动力学行为的新见解。这一研究计划的更广泛影响主要有两个方向。首先，在一些应用中，我们的基础研究成果可以作为长期实用指南实施，从药物输送微球的流体动力学靶向到塑料和药品加工。此外，我们实验室的研究生和本科生将经历密集的研究性培训，这也具有教育价值。

AbstractCTS-0425187N. Shapley, Columbia University Accumulation of Particulates in Complex Flows: Characterization by NMR Imaging The mission of this research is to probe the behavior of dispersed particulates (particles or droplets) in complex flows that are relevant to industrial and biological systems. Flows of concentrated dispersions (liquids containing many discrete particles or droplets) are found in many processes in the pharmaceutical, food, oil, and plastics industries, but their behavior is difficult to control, generally due to nonuniform distributions of the continually interacting particles or droplets. The intellectual merit of this research derives from the goal of quantifying the distribution of particulates in complex flow geometries and time-dependent flows. In complex flows (where both shearing and elongation are present), existing continuum models of concentrated suspensions often do not predict observed particle distributions, numerical simulations in complex geometries are too overburdened by intensive computations to be practical, and experimental data are sparse. Our aim then is to acquire incisive sets of measurements of concentrated suspensions and emulsions in simplified model systems that capture key elements of real circulatory, bioreactor, or manufacturing processes. We will apply noninvasive nuclear magnetic resonance imaging (NMRI) along with optical methods to quantify concentration and velocity distributions in these systems and relate observations to particulate properties. The enormous capability of NMRI to be employed in opaque systems and both in vitro and in vivo opens up an entire new dimension of systems that are not accessible to optical techniques. The targeted element of complex flows that this study will address is particulate accumulation in disturbed flows. We aim to identify the most important system parameters determining particulate accumulation and to quantify particulate concentration and velocity profiles as benchmarks for testing continuum model predictions. The study is anticipated to reveal new insights into the behavior of dispersion dynamics. The broader impact of this research program has two main directions. First, there are the applications in which our fundamental research results can be implemented as practical guidelines in the long term, ranging from hydrodynamic targeting of drug delivery microspheres to plastics and pharmaceuticals processing. In addition, there is the educational value of the intensive research training that the graduate and undergraduates dents in our laboratory will experience.