GOALI: Population Balance Modeling: Fundamental Closures and Experimental Validation

GOALI：人口平衡建模：基本封闭和实验验证

基本信息

批准号：
1707046
负责人：
Christine Hrenya
金额：
$ 39.85万
依托单位：
University of Colorado at Boulder
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-09-01 至 2021-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1707046&HistoricalAwards=false
关键词：
GOALI Population Balance Modeling Fundamental

项目摘要

In nature, the flow of solid particles in avalanches and landslides can lead to quite devastating effects. In industrial processing, the flow of solid particles is inherent to the production of pharmaceuticals, oil and gas, chemicals, and agricultural products. To avoid comparable adverse effects, such as industrial accidents and lost productivity, it is important to predict and control the flow of these granular systems. However, the flow of solid particles is poorly understood and not easily modeled. Whereas models of liquid flow are a basic tenant of engineering and derived from basic physical principles, current models of solid particle flow rely on adjustable parameters, are empirical, and incorporate a number of gross simplifications. This research project uses computer simulations and state-of-the-art experiments to develop and validate theoretical models of flows of solid particles that are based on measurable quantities. In addition, this work supports the involvement of underrepresented groups, the training of junior researchers and students, and the involvement of students in an industrial-academic research partnership. Results from the project will be communicated to the general public via blog posts and a Twitter account.This project is focusing on the reliable prediction of the mass flow rate of solids when they are fluidized by the upward motion of a flowing gas. Existing empirical correlations for particle entrainment rate constants may vary by many orders of magnitude when applied to the same system. Current models are primarily limited by empiricism and development to a very particular situation. To develop a predictive understanding of fluidized granular systems, this research is deriving a closure for the continuum theory that is based on population and kinetic theory balances. The resulting model for cohesive-particle flows will require only measurable, physical quantities as inputs. The new continuum framework is being applied to the case of humidity-induced agglomeration. Numerical modeling with discrete element method simulations is being combined with non-intrusive shadowgraphy experiments to validate the new theory. A unique aspect of the work is the development of a novel microscopic (particle-particle) cohesion model that drives the closure of the macroscopic (continuum) theory.

在自然界中，雪崩和滑坡中的固体颗粒的流动会导致毁灭性的影响。在工业加工中，固体颗粒的流量是制药，油气，化学物质和农产品的生产所固有的。为了避免可比的不利影响，例如工业事故和生产力损失，重要的是要预测和控制这些颗粒系统的流动。但是，固体颗粒的流量很少，并且不容易建模。尽管液体流量的模型是工程的基本租户，并源自基本的物理原理，而当前的固体流量模型依赖于可调参数，但经验是经验，并且包含了许多总体简化。该研究项目使用计算机模拟和最先进的实验来开发和验证基于可测量数量的固体颗粒流的理论模型。此外，这项工作还支持代表性不足的群体，初级研究人员和学生的培训以及学生参与工业学术研究伙伴关系的参与。该项目的结果将通过博客文章和Twitter帐户传达给公众。该项目的重点是可靠的预测固体的质量流量，当它们通过流动气体的向上运动流动时。当应用于同一系统时，粒子夹带率常数的现有经验相关性可能会因许多数量级而有所不同。当前的模型主要受经验主义和发展的限制。为了对流化的颗粒系统进行预测理解，这项研究正在为基于人群和动力学理论平衡的连续性理论提供封闭。粘性粒子流的最终模型将仅需要可测量的物理量作为输入。新的连续框架正在应用于湿度引起的聚集的情况。具有离散元素方法模拟的数值建模与非侵入性阴影实验相结合，以验证新理论。这项工作的一个独特方面是开发一种新型的显微镜（粒子粒子）内聚模型，该模型驱动宏观（连续性）理论的关闭。