CAREER: Kinetic Behavior of Post-Flameout Ignition Events

职业：熄火后点火事件的动力学行为

• 批准号: 2047259
• 负责人: Nicole Labbe
• 金额: $ 50.11万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-12-01 至 2025-11-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2047259&HistoricalAwards=false
• 关键词: CAREER; Kinetic; Behavior; Post; Flameout

Flameout is an adverse event in aircraft operation in which the flame in the combustor is extinguished during flight. It can occur in fully operational engines under extreme flight conditions, presenting a critical safety issue for aviation. While chemical ignition behavior has been studied for aircraft on the ground before takeoff, far less is known about how the extreme conditions experienced after flameout at high altitude may influence the fundamental chemistry of ignition. This project will help to fill a critical knowledge gap by investigating the fundamental chemistry of post-flameout reignition, which is necessary in designing effective engineering strategies to re-light stalled aircraft engines at altitude. The project will use computational chemistry methods and fundamental experiments to understand the chemical mechanism of post-flameout ignition and determine how pressure and temperature influence the behavior of ignition. It includes strong educational and outreach components; training graduate and undergraduate students, developing mentoring programs at the college and national level, and creating virtual lab modules for combustion science education.The PI’s primary goal is to obtain a fundamental understanding of the chemical mechanism for ignition of jet fuel, which is critical in enabling the design of novel post-flameout ignition technology. She will use a combined theoretical and experimental approach to identify how the chemical pathways for ignition differ at takeoff and flameout conditions. The project will address two central research questions: 1) How does the mechanism for ignition vary at extreme temperature and pressure conditions? and 2) What is the effect of boosting ignition with thermal radical precursors after flameout? Two different jet fuel surrogates (JP-10 and a POSF 4658 surrogate) will be studied using electronic structure theory approaches to determine the relevant reactions for ignition, calculate the rates by which those reactions occur, and develop combustion kinetic models to predict their chemical behavior under relevant temperature and pressure conditions. To confirm the accuracy of the theoretical work, the study will use complementary experimental studies to detect combustion intermediate via photoionization mass spectrometry and infrared spectroscopy. Further, it will conduct a kinetic study of the effect of radical precursors as ignition boosting additives to assess their viability as a chemical solution to post-flameout re-ignition. The resultant fundamental understanding of aviation fuel ignition behavior at extreme conditions and in the presence of radical precursor additives is expected to spur new innovations in aviation safety engineering.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.

熄火是飞机飞行过程中燃烧室火焰熄灭的不良事件。它可能发生在极端飞行条件下完全运行的发动机中，这对航空来说是一个关键的安全问题。虽然飞机起飞前在地面上的化学点火行为已经被研究过，但对于高空熄火后经历的极端条件如何影响点火的基本化学成分，人们知之甚少。这个项目将通过研究熄火后再点火的基本化学来帮助填补一个关键的知识空白，这对于设计有效的工程策略以在高空重新点燃失速的飞机发动机是必要的。该项目将使用计算化学方法和基础实验来了解熄火后点火的化学机理，并确定压力和温度如何影响点火行为。它包括强大的教育和推广部分；培训研究生和本科生，开发学院和国家层面的指导计划，以及创建燃烧科学教育的虚拟实验室模块。PI的主要目标是对喷气燃料点火的化学机理有一个基本的了解，这对设计新的熄火后点火技术至关重要。她将使用理论和实验相结合的方法来确定在起飞和熄火条件下点火的化学路径如何不同。该项目将解决两个中心研究问题：1)在极端温度和压力条件下，点火机制如何变化？2)熄火后用热自由基前驱体助燃的效果如何？两种不同的喷气燃料替代品(JP-10和POSF 4658替代品)将使用电子结构理论方法进行研究，以确定相关的点火反应，计算这些反应发生的速率，并建立燃烧动力学模型来预测它们在相关温度和压力条件下的化学行为。为了验证理论工作的准确性，本研究将利用互补的实验研究，通过光电离质谱和红外光谱来检测燃烧中间体。此外，它还将对自由基前体作为点火助燃剂的效果进行动力学研究，以评估它们作为熄火后重新点火后的化学溶液的可行性。由此产生的对极端条件下和存在激进前体添加剂情况下的航空燃料点火行为的基本了解有望刺激航空安全工程方面的新创新。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。