Development of a thermodynamically consistent rheological constitutive equation for thixotropic suspensions connecting particle properties to thermodynamics and rheology

开发触变悬浮液的热力学一致流变本构方程，将颗粒特性与热力学和流变学联系起来

• 批准号: 1804911
• 负责人: Norman Wagner
• 金额: $ 31.12万
• 依托单位: University of Delaware
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-01 至 2023-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1804911&HistoricalAwards=false
• 关键词: Development; thermodynamically; consistent; rheological; constitutive

Many materials must have both solid-like and fluid-like properties during their processing and/or use. Examples include construction materials such as cement and asphalt, biological fluids such as blood, consumer products including toothpaste and hand-creams, naturally occurring muds, clays, and sediments, and polymers and pastes used in 3-D printing. To achieve the desired flow behavior, product formulators vary particle properties, such as size, shape, and surface coatings, add flow modifiers and gelling agents, and vary the processing conditions. However, there is no accurate method of predicting the flow behavior. This limits the development of many products and points to a gap in our scientific understanding of these important materials. This research will develop a new theoretical framework, to be validated by innovative experiments, to aid in this endeavor. The work should both improve our scientific understanding of these complex materials and provide engineering guidance for industry on improving processing. In addition, high school students, undergraduates and graduate students will be trained in this multidisciplinary research effort.More technically, this research addresses thixotropy, which is a ubiquitous, and often vexing, property of particle-containing complex fluids, pastes, and soft matter characterized by a complex, time-dependent rheology due to flow-microstructure coupling. Micromechanical approaches are inherently restricted to small scales of length and time, while at the larger scales of importance to engineering applications and processing, only phenomenological models exist. These are often restricted to shear flows, and contain internal parameters with ill-defined physical meaning. The principal investigators plan to remedy this by developing a fundamental and rigorous, multiscale theoretical framework and use this to develop truly predictive constitutive equations, which will be validated against advanced experiments on well-defined, model thixotropic systems. They will develop a new tensorial, multiscale microstructure-based framework that is thermodynamically consistent and generally applicable for all flows (i.e., cast in materially objective fashion). The theory is based on the most modern nonequilibrium thermodynamic (NET) formalism (GENERIC); the investigators at the University of Delaware are among the pioneers of this approach. Coarse graining of a newly derived population balance model based on particle properties for suspensions with yield stress and matching with the continuum model will fix the mesoscale parameters in the NET theory and result in a predictive constitutive model that can be rigorously tested and validated against exact analytical results as well as internationally recognized data on model concentrated suspensions in transient and oscillatory shear flows and non-viscometric flows, and directly against microstructure data obtained using RHEO-optical & RHEO-SANS, leveraging research supported by NIST. The proposed NET multiscale modeling with a simultaneous emphasis on both the rheology and the material's microstructure, combined with tight coordination with the leveraged experimental program sets this work apart from previous efforts. The research will lead to a new capability in the modeling and understanding of complex thixotropic systems that can significantly advance the rational formulation and processing of many materials of industrial and national importance.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

许多材料在加工和/或使用过程中必须具有固体状和流体状的特性。 例子包括水泥和沥青等建筑材料，血液，包括牙膏和手动奶油的消费产品，包括泥浆，粘土和沉积物，以及用于3-D打印中的聚合物和糊状物。 为了达到所需的流动行为，产品配方器会改变粒子特性，例如尺寸，形状和表面涂层，添加流动修饰符和胶凝剂，并改变处理条件。 但是，没有预测流动行为的准确方法。这限制了许多产品的开发，并指出了我们对这些重要材料的科学理解的差距。 这项研究将开发一个新的理论框架，并通过创新实验来验证这一努力。 这项工作都应改善我们对这些复杂材料的科学理解，并为行业改善加工提供工程指导。 此外，高中生，本科生和研究生将接受这项多学科研究工作的培训。从技术上讲，这项研究解决了触变的问题，这是一种无处不在且经常令人烦恼的，具有颗粒的复杂流体，糊状，糊状和软件特征的，具有复杂的，时间依赖于流量的流程学的特征。微机械方法固有地限于长度和时间的小尺度，而在对工程应用程序和加工的重要性范围内，仅存在现象学模型。这些通常仅限于剪切流，并包含具有不确定物理含义的内部参数。 首席研究人员计划通过开发基本和严格的多尺理理论框架来纠正此问题，并使用它来开发真正的预测构型方程，该方程将根据针对明确定义的模型触变系统的高级实验进行验证。他们将开发一个新的紧张，多尺度微观结构的框架，该框架在热力学上是一致的，通常适用于所有流动（即以物质客观的方式施放）。该理论基于最现代的非平衡热力学（净）形式主义（通用）；特拉华大学的调查人员是这种方法的先驱。新得出的人口平衡模型的粗粒子基于粒子特性，这些悬浮应力和与连续模型匹配的悬浮液将固定净理论中的中尺度参数，并导致预测的本构成模型，该模型可以对精确的分析结果进行严格验证，并在临时悬挂和临时悬架中对临时悬架进行了严格验证，并在临时悬架和触发器上进行了固定的数据，并在跨度和触发下进行了悬挂，并将其置于跨度的悬挂状态，并依次进行悬挂，并依次进行悬挂和触发效应和触发范围。使用Rheo-Optical＆Rheo-Sans获得的微观结构数据，利用NIST支持的研究。拟议的净多尺度建模，同时着重于流变学和材料的微观结构，再加上与杠杆实验计划的紧密协调结合，使这项工作与以前的努力不同。 这项研究将导致对复杂触变系统的建模和理解的新能力，这些能力可以显着提高许多工业和国家重要性的许多材料的理性制定和处理。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子和更广泛影响的评估来通过评估来获得支持的。

项目成果

Erratum: “Tensorial formulations for improved thixotropic viscoelastic modeling of human blood” [J. Rheol. 66, 327 (2022)]

勘误表：“用于改进人体血液触变粘弹性模型的张量公式”[J.

• DOI: 10.1122/8.0000662
• 发表时间: 2023
• 期刊: Journal of Rheology
• 影响因子: 3.3
• 作者: Armstrong, Matthew;Pincot, Andre;Jariwala, Soham;Horner, Jeff;Wagner, Norman;Beris, Antony
• 通讯作者: Beris, Antony

Erratum: “Flux-based modeling of heat and mass transfer in multicomponent systems” [Phys. Fluids 34 , 033113 (2022)]

勘误表：“多组分系统中基于通量的传热和传质建模”[Phys.

• DOI: 10.1063/5.0094701
• 发表时间: 2022
• 期刊: Physics of Fluids
• 影响因子: 4.6
• 作者: Beris, Antony N.;Jariwala, Soham;Wagner, Norman J.
• 通讯作者: Wagner, Norman J.

Physiology-based parameterization of human blood steady shear rheology via machine learning: a hemostatistics contribution

• DOI: 10.1007/s00397-023-01402-2
• 发表时间: 2023-06-27
• 期刊: RHEOLOGICA ACTA
• 影响因子: 2.3
• 作者: Farrington，Sean;Jariwala，Soham;Beris，Antony N. N.
• 通讯作者: Beris，Antony N. N.

Recent advances in blood rheology: a review

• DOI: 10.1039/d1sm01212f
• 发表时间: 2021-11-05
• 期刊: SOFT MATTER
• 影响因子: 3.4
• 作者: Beris, Antony N.;Horner, Jeffrey S.;Wagner, Norman J.
• 通讯作者: Wagner, Norman J.

Tensorial formulations for improved thixotropic viscoelastic modeling of human blood

• DOI: 10.1122/8.0000346
• 发表时间: 2022-03-01
• 期刊: JOURNAL OF RHEOLOGY
• 影响因子: 3.3
• 作者: Armstrong, Matthew;Pincot, Andre;Beris, Antony
• 通讯作者: Beris, Antony