The Role of HO2 and RO2 Radicals in Preignition Reaction Chemistry

HO2 和 RO2 自由基在预点火反应化学中的作用

• 批准号: 1335760
• 负责人: Nicholas Cernansky
• 金额: $ 28.5万
• 依托单位: Drexel University
• 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: 2013-07-15 至 2017-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1335760&HistoricalAwards=false
• 关键词: Role; HO2; RO2; Radicals; Preignition

1335760CernanskyIn an effort to reduce emissions and fuel consumption, next generation ground transportation engines are expected to operate on cycles that employ Low Temperature Combustion (LTC). However, the underlying chemical kinetics and rate limiting steps in LTC have not been directly explored because of an inability to measure the key chemical constituents, hydroperoxy (HO2) and alkylperoxy (RO2) radicals, that control the process. In this study, a new laser absorption diagnostic combining two more traditional techniques will be employed to overcome this measurement problem and allow direct measurement of these peroxy radicals at preignition conditions, with the goal of developing a fundamental understanding of the underlying chemistry. The new diagnostic, cavity enhanced magneto-optical rotation (CEMOR), combines cavity enhanced ringdown spectroscopy which provides the sensitivity to measure the radicals and magneto-optic rotation which provides the selectivity necessary to eliminate interference from other compounds with similar absorption characteristics. This work will aid in the design of the next generation engine systems with increased efficiency and reduced emissions. The broader impact of the work will include training students in combustion science and state-of-the-art optical diagnostics techniques. The data collected in this effort will provide necessary information to further understand combustion chemistry, its role in the generation of greenhouse gases, and the subsequent effect on climate change. Efforts will be made to enhance minority student recruitment and participation in research and graduate education. Outreach activities include NSF's RET and REU site programs.

为了减少排放和燃料消耗，下一代地面运输发动机有望采用低温燃烧（LTC）循环运行。然而，由于无法测量控制这一过程的关键化学成分——氢过氧（HO2）和烷基过氧（RO2）自由基，LTC中潜在的化学动力学和限速步骤尚未直接探索。在这项研究中，一种新的激光吸收诊断结合了两种更传统的技术，将被用来克服这一测量问题，并允许在预点燃条件下直接测量这些过氧自由基，目标是发展对潜在化学的基本理解。新的诊断，腔增强磁光旋转（CEMOR），结合了腔增强衰荡光谱，提供了测量自由基的灵敏度和磁光旋转，提供了必要的选择性，以消除其他具有类似吸收特性的化合物的干扰。这项工作将有助于下一代发动机系统的设计，提高效率，减少排放。这项工作的更广泛的影响将包括培训学生在燃烧科学和最先进的光学诊断技术。在这项工作中收集的数据将为进一步了解燃烧化学、其在温室气体产生中的作用以及随后对气候变化的影响提供必要的信息。加强少数民族学生招生和参与研究和研究生教育。外展活动包括NSF的RET和REU站点计划。