Development and Validation of Particle-Phase Stress Constitutive Models for Non-Spherical Particles

非球形颗粒的颗粒相应力本构模型的开发和验证

• 批准号: 0854005
• 负责人: Jennifer Curtis
• 金额: $ 30万
• 依托单位: University of Florida
• 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: 2009-03-01 至 2014-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0854005&HistoricalAwards=false
• 关键词: Development; Validation; Particle; Phase; Stress

0854005Curtis, Jennifer Virtually all solid handling operations involve particles that are non-spherical in shape. However, most fundamental studies of granular material undertaken to date have involved spherical particles. Hence, there is a current significant disconnect between the model particles which are used in fundamental research studies and the characteristics of real particles dealt with in industry. While industrial practitioners comprehend fully that the influence of particle shape on particle flow behavior is significant, the role of particle shape in flowing granular systems is not understood. Hence, this proposal outlines a series of DEM simulations and complementary experiments which will result in a fundamental understanding of the influence of various specific features of particle shape on bulk particle flow behavior. In addition, results from the proposed work will yield the ability to predict general trends in flow and segregation behavior for non-spherical particles in a wide range of processes. The proposed work has three specific objectives: 1. To evaluate the quantitative accuracy of DEM simulations involving non-spherical particles modeled as collections of linked/overlapping spheres 2. To investigate the effect of particle shape on particle segregation in particle storage devices - a significant problem in industry 3. To develop and validate constitutive models for particle-phase stress of non-spherical particles that can be employed in CFD simulations The intellectual merit of the proposed work lies in the simulations and experiments, involving non-spherical interacting particles, which will be conducted, and the novel fundamental relationships and insights, pertaining to the influence of particle shape on bulk solids handling, which will be obtained. Real particle properties, not idealized smooth, round particles, must be considered before most industrially-relevant problems can be tackled. While a three-year project can not treat all aspects of real particles mixtures (e.g. particle size distribution, cohesion, electrostatic behavior, etc.), making headway on the effect of particle shape is a very significant advance in the field of granular flow. In addition, successful completion of this project fits well with the PI's longer term goal of developing first principles, predictive models that can be used for design, scale-up and optimization of particle flow processes. The proposed research will have broad impact since the research results are applicable to virtually all industrial granular flows which involve non-spherical particles. The research results will lead to improved constitutive models for CFD simulations, which are widely employed by industrial researchers. The results will also yield recommendations on ways to mitigate particle segregation during hopper discharge by altering the particle shape and/or particle size (based on equivalent volume diameter), as well as particle composition based on shape and size. Finally, the proposed research will have broad impact via involvement of students (one PhD student as well as minority undergraduate researchers) in the research, and the dissemination of the research findings to the scientific community, both through journal publications and through the education of large numbers of students and industrial personnel.

0854005Curtis，Jennifer几乎所有固体处理操作都涉及形状非球形的颗粒。但是，迄今为止对颗粒物材料进行的大多数基本研究涉及球形颗粒。因此，在基础研究研究中使用的模型粒子和实际粒子在行业中处理的特征之间存在着明显的断开连接。虽然工业实践者完全理解粒子形状对粒子流动行为的影响很重要，但尚不清楚粒子形状在流动颗粒系统中的作用。因此，该建议概述了一系列DEM模拟和互补实验，这将导致对粒子形状各种特定特征对散装粒子流动行为的影响的基本了解。此外，提议的工作的结果将产生预测在广泛过程中非球形颗粒流动和隔离行为的一般趋势的能力。 The proposed work has three specific objectives: 1. To evaluate the quantitative accuracy of DEM simulations involving non-spherical particles modeled as collections of linked/overlapping spheres 2. To investigate the effect of particle shape on particle segregation in particle storage devices - a significant problem in industry 3. To develop and validate constitutive models for particle-phase stress of non-spherical particles that can be employed in CFD simulations The intellectual merit of the提出的工作在于涉及将进行的非球形相互作用粒子以及新颖的基本关系和见解的模拟和实验，与粒子形状对散装固体处理的影响有关，将获得。在解决大多数与工业相关的问题之前，必须考虑实际的粒子特性，不是理想化的光滑，圆形颗粒。虽然一个三年的项目无法处理真实颗粒混合物的所有方面（例如粒度分布，内聚力，静电行为等），但在颗粒形状的效果方面取得了进展，这在颗粒流量领域非常重要。此外，该项目的成功完成非常符合PI的长期目标，即制定第一原理，可用于设计，扩展和优化粒子流程过程的预测模型。拟议的研究将产生广泛的影响，因为研究结果适用于几乎所有涉及非球形颗粒的工业颗粒流。研究结果将导致改善CFD模拟的构成模型，该模型被工业研究人员广泛使用。结果还将通过改变粒子形状和/或粒径（基于等效的体积直径）以及基于形状和尺寸的粒子组成，从而产生有关在料斗放电过程中减轻颗粒分离方法的方法的建议。最后，拟议的研究将通过学生参与研究，以及通过期刊出版物以及大量学生和工业人员的教育，将研究结果传播给科学界。