UNS: Extension of Lean Flammability Limit by Plasma Enhancement in Stratified Flames

1510709 （Chen）低温、稀薄燃烧可实现汽车和喷气发动机等燃烧装置的低排放水平和高效率。提出的研究调查了电场对燃料稀薄燃烧的影响，并寻求扩大超低温燃烧可行的极限。它还将研究活动与本科生和研究生的教育计划相结合，旨在为燃烧科学领域的下一代工程师和科学家提供对有前途的技术的基本理解。采用数值模拟和实验相结合的方法研究了分层条件下火焰支撑的机理，研究了外加电场对分层甲烷火焰低可燃性极限和火焰速度的影响。目标是研究在维持超稀薄条件下，在实际设备中可以维持多大程度的稳定燃烧，特别是阐明与火焰附近运输相关的热和化学效应的相对贡献。实验组件将用于验证模拟中使用的模型，并确认喷射和点火策略的有效性。获得的新知识将成为进一步提高发动机效率的基础。

1510709 (Chen)Low temperature, lean combustion enables low emission levels and high efficiencies of combustion devices such automobiles and jet engines. The proposed study investigates the effect of electrical field on the fuel-lean combustion and seeks to extend the limit where extra-low temperature combustion is viable. It also integrates the research activities with the education programs of undergraduate and graduate students, aiming to provide a fundamental understanding of promising technologies to the next generation of engineers and scientists in the field of combustion science.The mechanisms of flame support under stratified conditions are investigated with a combined numerical simulations and experimental approach, on the effect of an external electric field on the lean flammability limit and flame speed of a stratified methane flame. The goals are to investigate to what extent stable combustion can be maintained in practical devices while sustaining ultra-lean conditions and, specifically, to elucidate the relative contributions of thermal and chemical effects associated with transport in the vicinity of the flame. The experimental component will be used for validation of the models used in the simulations and to confirm the efficacy of the injection and ignition strategies. The new knowledge gained will form the basis for further gains in engine efficiency.