Collaborative Research: Experimental and numerical study on the Reynolds number dependence of surfaces in von Karman turbulent swirling flows

合作研究：冯卡门湍流旋流中表面雷诺数依赖性的实验和数值研究

• 批准号: 1805921
• 负责人: Fabrizio Bisetti
• 金额: $ 25万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1805921&HistoricalAwards=false
• 关键词: Collaborative; Research; Experimental; numerical; study

The growth of surfaces, thought of as infinitely thin interfaces that separate regions occupied by fluids with different properties, is a process of intrinsic and practical interest with wide ranging applications in nature, science, and technical devices. As dissimilar fluids mix and interact at interface that separates them, the quantitative characterization of the rates of growth and destruction of surfaces is of critical importance. A comprehensive theory that describes these processes in turbulent flows, which are the most common flows encountered, is unavailable at present. The end goal of the project is to formulate a systematic theory that describes the dynamics of surfaces in turbulent flows depending on the state of the motion of the fluid. A comprehensive theory on the dynamics of surfaces will augment the general theory of turbulent flows, including flows with mixing and chemical reaction, which are found in chemical and energy conversion systems. In addition, this project will improve the understanding of physical processes observed in nature, such as cloud formation, where the evolution of interfaces is the rate limiting process. Thus, although the work is fundamental in nature, it has the potential for broad impacts in science and technology. The project will support the education of two graduate students, and it will also include significant outreach educational activities, which will focus on engaging grades 4-7 students in scientific discovery by investigating the properties of fluid mixing.The overarching goal of the project is to quantify the dependence of the evolution of surfaces in turbulent flows on the Reynolds number. We combine direct numerical simulations and measurements in a novel von Karman turbulent swirling flow setup featuring a shear-driven closed flow between counter-rotating impellers with fully developed turbulence at high Reynolds numbers. The evolution of surfaces in this canonical laboratory flow is tracked quantitatively, while the parameters that describe the flow configuration are varied judiciously to probe a broad range of conditions in the parameter space where different effects are believed to play a role on the evolution of surfaces. The project will fill this broad goal by focusing on two thrusts: (i) Prove or disprove the Reynolds number dependence of the area and growth rates of large surfaces in turbulent flows; (ii) Identify the parameters that scale the evolution of surfaces in turbulent flow through a detailed analysis of the terms in the transport equation for surfaces in turbulence. The direct numerical simulations of the entire device include all geometrical complexities, while experiments feature a novel manner of generating surfaces on demand and state-of the art volumetric measurements of the velocity field and 3D representation of the turbulent. This novel and unique research program is unprecedented as it includes both the broadest range and highest Reynolds numbers ever considered in the study of surfaces in turbulent flows.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.

表面的生长被认为是无限薄的界面，将具有不同特性的流体占据的区域分开，是一个具有内在和实际意义的过程，在自然、科学和技术设备中具有广泛的应用。当不同的流体在分隔它们的界面处混合和相互作用时，表面生长和破坏速率的定量表征至关重要。目前还没有一种全面的理论来描述湍流中的这些过程，湍流是最常见的流动。该项目的最终目标是制定一个系统理论，根据流体运动状态来描述湍流中表面的动力学。关于表面动力学的综合理论将增强湍流的一般理论，包括在化学和能量转换系统中发现的混合流和化学反应流。此外，该项目将提高对自然界中观察到的物理过程的理解，例如云的形成，其中界面的演化是速率限制过程。因此，尽管这项工作本质上是基础性的，但它具有对科学和技术产生广泛影响的潜力。该项目将支持两名研究生的教育，还将包括重要的外展教育活动，重点是通过研究流体混合的特性，让 4-7 年级的学生参与科学发现。该项目的总体目标是量化湍流中表面演化对雷诺数的依赖性。我们将直接数值模拟和测量结合在一种新颖的冯卡门湍流旋流装置中，该装置具有反向旋转叶轮之间的剪切驱动闭合流，以及在高雷诺数下充分发展的湍流。定量跟踪这个规范实验室流动中的表面演化，同时明智地改变描述流动配置的参数，以探测参数空间中的广泛条件，其中不同的效应被认为对表面的演化发挥作用。该项目将通过关注两个重点来实现这一广泛目标：（i）证明或反驳湍流中大表面面积和增长率的雷诺数依赖性； (ii) 通过对湍流中表面传输方程中的项进行详细分析，确定缩放湍流中表面演化的参数。整个设备的直接数值模拟包括所有几何复杂性，而实验则采用了一种按需生成表面的新颖方式以及最先进的速度场体积测量和湍流的 3D 表示。这项新颖而独特的研究计划是前所未有的，因为它包括了湍流表面研究中有史以来最广泛的范围和最高的雷诺数。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值进行评估，被认为值得支持以及更广泛的影响审查标准。

项目成果

Evolution and scaling of the peak flame surface density in spherical turbulent premixed flames subjected to decaying isotropic turbulence

经受衰减各向同性湍流的球形湍流预混火焰中峰值火焰表面密度的演变和缩放

• DOI: 10.1016/j.proci.2020.06.042
• 发表时间: 2020
• 期刊: Proceedings of the Combustion Institute
• 影响因子: 3.4
• 作者: Kulkarni, Tejas;Bisetti, Fabrizio
• 通讯作者: Bisetti, Fabrizio

Analysis of the development of the flame brush in turbulent premixed spherical flames

湍流预混球形火焰中火焰刷的发展分析

• DOI: 10.1016/j.combustflame.2021.111640
• 发表时间: 2021
• 期刊: Combustion and Flame
• 影响因子: 4.4
• 作者: Kulkarni, Tejas;Bisetti, Fabrizio
• 通讯作者: Bisetti, Fabrizio

Direct numerical simulations of the swirling von Kármán flow using a semi-implicit moving immersed boundary method

使用半隐式移动浸没边界法对旋转冯卡门流进行直接数值模拟

• DOI: 10.1016/j.compfluid.2021.105132
• 发表时间: 2021
• 期刊: Computers & Fluids
• 影响因子: 2.8
• 作者: Kasbaoui, M. Houssem;Kulkarni, Tejas;Bisetti, Fabrizio
• 通讯作者: Bisetti, Fabrizio

Reynolds number scaling of burning rates in spherical turbulent premixed flames

球形湍流预混火焰中燃烧速率的雷诺数缩放

• DOI: 10.1017/jfm.2020.784
• 发表时间: 2021
• 期刊: Journal of Fluid Mechanics
• 影响因子: 3.7
• 作者: Kulkarni, Tejas;Buttay, Romain;Kasbaoui, M. Houssem;Attili, Antonio;Bisetti, Fabrizio
• 通讯作者: Bisetti, Fabrizio

Surface morphology and inner fractal cutoff scale of spherical turbulent premixed flames in decaying isotropic turbulence

衰减各向同性湍流中球形湍流预混火焰的表面形貌和内分形截止尺度

• DOI: 10.1016/j.proci.2020.06.117
• 发表时间: 2020
• 期刊: Proceedings of the Combustion Institute
• 影响因子: 3.4
• 作者: Kulkarni, Tejas;Bisetti, Fabrizio
• 通讯作者: Bisetti, Fabrizio