CAREER: Impact of Turbulence on Mechanisms of Combustion Instability

职业：湍流对燃烧不稳定机制的影响

基本信息

批准号：
1749679
负责人：
Jacqueline O'Connor
金额：
$ 50万
依托单位：
Pennsylvania State Univ University Park
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：
2018-06-01 至 2024-05-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1749679&HistoricalAwards=false
关键词：
CAREER Impact Turbulence Mechanisms Combustion

项目摘要

Combustion instability is an issue that affects many critical power and propulsion technologies, including jet engines, power-generation gas turbines, rockets, boilers, and process furnaces. Significant questions remain about how turbulence alters flame behavior during instability. In particular, in high-performance engines, does the turbulence/flame interaction change the instability feedback mechanisms and do the present numerical models include the correct physics? The proposed work addresses these questions using a systematic experimental approach to examine various key aspects of combustion instability. Advanced laser diagnostics will be used to image the flowfield and the flame, unlocking the coupling between turbulence and the instability feedback loop. The PI will also work with many other early-career faculty to effectively disseminate the results of this research and enhance the educational experience of students. In particular, the PI will facilitate an online network of early-career researchers to share research and teaching materials. This will ease the transition into faculty careers and promote high-quality thermofluids education at universities across the United States.The technical goal of the proposed work is to understand the impact of turbulence on three critical components of the thermoacoustic feedback loop: the hydrodynamic instability of the flowfield that determines the susceptibility of the flow to external disturbances; the coupling mechanisms that drive heat release rate oscillations; and the mechanism by which these disturbances create heat release rate oscillations in non-flamelet regimes. This systematic approach uses theory-based experimental design to probe the ways in which turbulence impacts flow stability, coupling-mechanism physics, and flame behavior within the framework of combustion instability. The overarching intellectual merit contribution will be made in the formulation of the combustion instability regime diagram that describes the behavior of flames during thermoacoustic instability over a range of operating conditions. In following this framework, this work will have significant impacts on fundamental understanding of turbulent flames and combustion instability, the ability to predict combustion instability in industry-relevant devices, and the PIs career development. The results of this work will also feed into the development, implementation, and dissemination of case studies for undergraduate and graduate audiences. The case studies will focus on combustion-related issues, exposing a range of students to the importance of combustion in society; case studies will be disseminated through a network of early-career faculty through an online portal. The development of the case studies is rooted in theory-based educational design, including best-practices for the formation of online content, research-based techniques for improving recruitment and retention of under-served student populations, and the robust development of a community of practice for early-career faculty centered on incorporating combustion science into the classroom.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.

燃烧不稳定是一个影响许多关键动力和推进技术的问题，包括喷气发动机、发电燃气轮机、火箭、锅炉和工艺炉。关于湍流如何改变不稳定期间的火焰行为仍然存在重大问题。特别是，在高性能发动机中，湍流/火焰相互作用是否会改变不稳定反馈机制，并且当前的数值模型是否包含正确的物理场？拟议的工作使用系统实验方法来检查燃烧不稳定性的各个关键方面来解决这些问题。先进的激光诊断将用于对流场和火焰进行成像，解锁湍流和不稳定性反馈回路之间的耦合。 PI还将与许多其他早期职业教师合作，有效传播这项研究成果并增强学生的教育体验。特别是，PI 将促进早期职业研究人员的在线网络共享研究和教学材料。这将有助于教师职业生涯的过渡，并促进美国各地大学的高质量热流体教育。拟议工作的技术目标是了解湍流对热声反馈回路三个关键组成部分的影响：流场决定了流动对外部扰动的敏感性；驱动热释放率振荡的耦合机制；以及这些扰动在非小火焰状态下产生热释放率振荡的机制。这种系统方法使用基于理论的实验设计来探讨湍流影响燃烧不稳定框架内的流动稳定性、耦合机制物理和火焰行为的方式。总体智力贡献将在燃烧不稳定状态图的制定中做出，该图描述了在一系列操作条件下热声不稳定期间火焰的行为。遵循该框架，这项工作将对湍流火焰和燃烧不稳定性的基本理解、预测行业相关设备中燃烧不稳定性的能力以及 PI 的职业发展产生重大影响。这项工作的结果还将用于针对本科生和研究生受众的案例研究的开发、实施和传播。案例研究将重点关注与燃烧相关的问题，让一系列学生了解燃烧在社会中的重要性；案例研究将通过在线门户网站通过早期职业教师网络进行传播。案例研究的发展植根于基于理论的教育设计，包括形成在线内容的最佳实践、用于改善招收和保留服务不足的学生群体的基于研究的技术，以及社区的强劲发展。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和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

期刊论文数量（10）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Role of Turbulence in Precessing Vortex Core Dynamics

湍流在进动涡核动力学中的作用

DOI：
发表时间：
2019
期刊：
ASME Turbo Expo
影响因子：
0
作者：
Karmarkar, Ashwini;Frederick, Mark;Clees, Sean;Mason, Danielle;O'Connor, Jacqueline
通讯作者：
O'Connor, Jacqueline

Impact of turbulence on the coherent flame dynamics in a bluff-body stabilized flame

DOI：
10.1016/j.proci.2020.08.059
发表时间：
2021-04-10
期刊：
PROCEEDINGS OF THE COMBUSTION INSTITUTE
影响因子：
3.4
作者：
Karmarkar, Ashwini;Tyagi, Ankit;O'Connor, Jacqueline
通讯作者：
O'Connor, Jacqueline

Impact of precessing vortex core dynamics on the thermoacoustic instabilities in a swirl-stabilized combustor

旋流稳定燃烧室中进动涡核动力学对热声不稳定性的影响

DOI：
10.1017/jfm.2022.610
发表时间：
2022
期刊：
Journal of Fluid Mechanics
影响因子：
3.7
作者：
Karmarkar, Ashwini;Gupta, Saarthak;Boxx, Isaac;Hemchandra, Santosh;O'Connor, Jacqueline
通讯作者：
O'Connor, Jacqueline

Understanding the role of flow dynamics in thermoacoustic combustion instability