Computational Investigation of the Effects of Surfactants on Bubble Dynamics, Bubble Swarm Interactions and Turbulent Flow

表面活性剂对气泡动力学、气泡群相互作用和湍流影响的计算研究

• 批准号: 1705630
• 负责人: Kannan Premnath
• 金额: $ 31.37万
• 依托单位: University of Colorado at Denver-Downtown Campus
• 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: 2017-06-15 至 2021-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1705630&HistoricalAwards=false
• 关键词: Computational; Investigation; Effects; Surfactants; Bubble

Surface active materials or surfactants in two-phase, bubbly flow mixtures are used in a number of areas of important scientific and technological interest, including those in chemical, bio-molecular, power and petroleum engineering applications. They can significantly change the interfacial dynamics, fluid motion and structure of macroscale bubble aggregates, and are known to cause clustering of bubbles and turbulence suppression near walls. However, the fundamental details of the underlying physical mechanisms associated with such observations are not yet completely known, and elucidation through modeling will have direct impact on the design and scale-up and the operation of engineering systems. Such complex fluid systems involve both bulk and molecular effects, which are mediated by the interfacial dynamics and driven by the fluid motion present major challenges. Their understanding, especially for bubble swarm interactions in the inertia dominated flow regimes, is generally limited to experimental visualization results and empirical data. This project aims to perform large scale simulations using innovative computational techniques at the forefront in their development for the investigation and elucidation of the underlying processes in prototypical flows of surfactant-laden two-phase bubbly systems and swarms. Successful implementation of this research will yield new tools, rich sets of data and physical insights under unprecedented conditions that will be of interest to a wide community of researchers. The project will impact the education in a number of ways, including interdisciplinary training and research participation of graduate and undergraduate students. The results of this proposed research, which lies at the borderline between mechanical/chemical engineering, and physics and computational science, will be disseminated broadly in journal papers and conferences, and the new methods and codes developed under this project will be readily available as open sources. This project has the potential to transform the way the surfactant effects are modeled, qualitative and quantitative understanding of the surfactant-laden bubbly flows in various nonlinear flow regimes. The application of a three-dimensional multiphase flow model using a cascaded lattice Boltzmann (LB) formulation is at the cutting edge of current research and will potentially make fundamental advances in the modeling and simulation capabilities to study the role of surfactant effects on convection dominated bubble dynamics and swarm interactions. Its kinetic origins facilitate incorporation of mesoscopic models and the LB method is remarkably successful in complex fluid flow applications with natural parallelization capabilities. The surfactants and the bulk fluids are represented as dipoles and van der Waals fluids, respectively, which, in turn, generate surfactant-fluid, surfactant-surfactant mean-field force interactions at mesoscopic scales that govern the alignment of the surface agents, phase segregation and surface tension effects. The use of a central moment formulation in the cascaded LB method offers enhanced physical and numerical simulation capabilities. This innovative computational approach will be brought to bear on performing a systematic study of the effect of the characteristic parameters to elucidate physical understanding for the following prototypical cases: surfactant-laden bubble breakup processes in homogeneous turbulence, surfactant effects on the motion of a single bubble in a shear-driven turbulent channel flow, and buoyancy-driven motion of a single and a pair of surfactant-laden bubbles to study their path instabilities, rise velocities, drag and lift forces and wake structures. This will offer researchers fundamental insights into the underlying mechanisms involved, including the role of surfactants on cluster formation in swarms and phase diagrams based on characteristic parameters delineating the various regimes of bubble paths and deformations thereby clarifying the role of surfactants on path instabilities (Leonardo's paradox). Another major outcome will be in the development of predictive closure relations incorporating surfactant effects for mixture models.

两相泡状流混合物中的表面活性材料或表面活性剂用于许多重要的科学和技术领域，包括化学、生物分子、动力和石油工程应用中的那些领域。它们可以显著改变界面动力学、流体运动和宏观尺度气泡聚集体的结构，并且已知会引起气泡的聚集和壁附近的湍流抑制。然而，与这些观测相关的基本物理机制的基本细节尚未完全了解，通过建模进行说明将对工程系统的设计和放大以及操作产生直接影响。这种复杂的流体系统涉及体积和分子效应，这是介导的界面动力学和流体运动的驱动提出了重大挑战。他们的理解，特别是在惯性占主导地位的流态中的气泡群相互作用，通常仅限于实验可视化结果和经验数据。该项目旨在使用创新的计算技术进行大规模模拟，这些技术处于其发展的最前沿，用于调查和阐明充满表面杂质的两相泡状系统和群的原型流动中的基本过程。这项研究的成功实施将在前所未有的条件下产生新的工具，丰富的数据集和物理见解，这将引起广大研究人员的兴趣。该项目将以多种方式影响教育，包括研究生和本科生的跨学科培训和研究参与。这一拟议研究的结果位于机械/化学工程与物理学和计算科学之间的边界，将在期刊论文和会议上广泛传播，在该项目下开发的新方法和代码将作为开放源代码随时可用。该项目有可能改变表面活性剂效应的建模方式，定性和定量地了解各种非线性流态中的表面活性剂负载泡状流。三维多相流模型的应用，使用级联格子玻尔兹曼（LB）配方是在当前研究的前沿，并有可能在建模和模拟能力，研究对流为主的气泡动力学和群相互作用的表面活性剂的作用，取得根本性的进展。它的动力学起源促进了介观模型的结合，LB方法在具有自然并行化能力的复杂流体流动应用中非常成功。表面活性剂和本体流体分别表示为偶极和货车德瓦尔斯流体，其进而在介观尺度下产生表面活性剂-流体、表面活性剂-表面活性剂平均场力相互作用，所述介观尺度支配表面剂的排列、相分离和表面张力效应。在级联LB方法中使用中心矩公式提供了增强的物理和数值模拟能力。这种创新的计算方法将用于对特征参数的影响进行系统的研究，以阐明对以下典型情况的物理理解：均匀湍流中表面活性剂对气泡破碎过程的影响，剪切驱动湍流槽道流中表面活性剂对单个气泡运动的影响，和浮力驱动运动的单个和一对表面负载气泡，以研究其路径不稳定性，上升速度，阻力和升力和尾流结构。这将为研究人员提供有关基本机制的基本见解，包括表面活性剂对群集形成的作用，以及基于特征参数的相图，这些参数描绘了气泡路径和变形的各种制度，从而澄清了表面活性剂对路径不稳定性的作用（列奥纳多悖论）。另一个主要成果将是在预测封闭关系的发展，将表面活性剂的混合物模型的影响。

项目成果

Cascaded lattice Boltzmann modeling and simulations of three-dimensional non-Newtonian fluid flows

• DOI: 10.1016/j.cpc.2021.107858
• 发表时间: 2019-08
• 期刊: Comput. Phys. Commun.
• 作者: S. Adam;Farzaneh Hajabdollahi;K. Premnath

Surfactant effects on interfacial flow and thermal transport processes during phase change in film boiling

表面活性剂对薄膜沸腾相变过程中界面流动和热传输过程的影响

• DOI: 10.1063/1.5010333
• 发表时间: 2018
• 期刊: Physics of Fluids
• 影响因子: 4.6
• 作者: Premnath, Kannan N.;Hajabdollahi, Farzaneh;Welch, Samuel W. J.
• 通讯作者: Welch, Samuel W. J.

Central Moments-based Cascaded Lattice Boltzmann Method for Thermal Convective Flows in Three-Dimensions

• DOI: 10.1016/j.ijheatmasstransfer.2017.12.085
• 发表时间: 2017-10
• 期刊: arXiv: Computational Physics
• 作者: Farzaneh Hajabdollahi;K. Premnath

Central moment lattice Boltzmann method using a pressure-based formulation for multiphase flows at high density ratios and including effects of surface tension and Marangoni stresses

• DOI: 10.1016/j.jcp.2020.109893
• 发表时间: 2019-09
• 期刊: J. Comput. Phys.
• 作者: Farzaneh Hajabdollahi;K. Premnath;S. Welch

Cascaded lattice Boltzmann method based on central moments for axisymmetric thermal flows including swirling effects

• DOI: 10.1016/j.ijheatmasstransfer.2018.09.059
• 发表时间: 2018-06
• 期刊: International Journal of Heat and Mass Transfer
• 影响因子: 5.2
• 作者: Farzaneh Hajabdollahi;K. Premnath;S. Welch