Multiscale Simulations of Multiphase Flows

多相流的多尺度模拟

• 批准号: 1335913
• 负责人: Gretar Tryggvason
• 金额: $ 33.87万
• 依托单位: University of Notre Dame
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1335913&HistoricalAwards=false
• 关键词: Multiscale; Simulations; Multiphase; Flows

1335913PI: TryggvasonDirect numerical simulations (DNS) have made significant contribution to our understanding of multiphase flows over the last two decades. As their use has increased, and increasingly complex systems are being examined, two major issues have emerged. The first is that in many situations small-scale features emerge that require excessive (and often unachievable) resolution. These features either emerge spontaneously as thin films or threads or due to the addition of new physics that takes place on time and length scales very different than those of the flow. The second issue is that the wealth of data generated by DNS now far outstrips what can be used in standard models for the average flow field. This project is aimed at addressing both issues through the following two objectives. (1) The use of embedded analytical description for accurate capture of topology changes in simulations of multiphase flows. The approach is based on the observation that many small-scale features (films, threads, boundary layers, etc.) have a relatively simple structure and can therefore be described relatively accurately by analytical or semi-analytical models that are evolved concurrently with the fully resolved larger-scale motion. In this project, earlier work of films and mass transfer will be extended to capture accurately the rupture of films and threads. (2) Explore the evolution of various advanced statistical ways to describe the topology of complex multiphase flows. Such quantities include the area concentration tensor, average surface tension effects, and others, yet to be determined. The goal is to establish how these quantities correlate with the structure of the flow, and to attempt to model their evolution. Particular attention will be focused on how these quantities change during topology changes, their influence on the overall evolution of the flow, and the importance of predicting rupture accurately. The numerical methods will be made available through an online repository, along with a thorough documentation of the methodology and the use of the codes.Multiphase flows are critical in energy conversion, material processing, chemical industry, atmospheric processes, and living systems. Incremental improvement in the efficiency of such processes translates into billions of dollars in savings and new discoveries have the potential to transform whole industries. Computational studies will bring about both incremental and transformative changes in the management of multiphase systems. Educational material aimed at lowering the barrier to entry for new researchers will be developed and undergraduate students will be exposed to the area through research projects.This project is partially funded by an CISE/ACI CIF21 Venture Fund for Software Reuse.

1335913PI：tryggvasondirect数值模拟（DNS）为我们在过去二十年中对多相流的理解做出了重大贡献。随着它们使用的增加，正在检查日益复杂的系统，出现了两个主要问题。首先是，在许多情况下，小规模特征出现了，需要过多（通常是无法实现的）分辨率。这些特征要么自发地以薄膜或线形式出现，要么是由于添加了按时间和长度尺度的新物理学添加与流量的尺度截然不同。第二个问题是，DNS生成的大量数据现在远远超过了平均流场的标准模型中可以使用的内容。该项目旨在通过以下两个目标解决这两个问题。 （1）使用嵌入式分析描述准确捕获多相流的拓扑变化。该方法基于这样的观察结果，即许多小规模特征（膜，线，边界层等）具有相对简单的结构，因此可以通过分析或半分析模型相对准确地描述，这些模型与完全分辨的大规模运动同时演变。在这个项目中，将扩展电影和传质的早期工作，以准确捕获膜和线的破裂。 （2）探索描述复杂多相流的拓扑的各种先进统计方法的演变。这样的数量包括面积浓度张量，平均表面张力效应等，尚未确定。目的是确定这些数量如何与流量的结构相关，并试图建模其进化。特别关注这些数量在拓扑变化过程中如何变化，它们对流动总体演变的影响以及准确预测破裂的重要性。数值方法将通过在线存储库提供，以及有关方法和使用代码的详尽文档。多语言流在能源转换，材料处理，化学工业，化学工业，大气过程和生活系统中至关重要。此类过程效率的增量提高转化为数十亿美元的储蓄，而新发现有可能改变整个行业。计算研究将带来多相系统管理的增量和变革性变化。旨在降低新研究人员进入障碍的教育材料将开发，并通过研究项目将本科生接触到该地区。该项目部分由CISE/ACI CIF21软件再利用的CISE/ACI CIF21风险投资资助。