Experimental investigation of turbulence-chemistry interaction for flame kernel development in a spark-ignition (SI) engine

随着能源和环境问题的日益增加，显然需要提高燃料经济性并减少内燃机（IC）的排放。为了更好地理解和改善内燃机的燃烧性能，需要解决火花点火（SI）发动机中发展火焰前锋的化学反应相互作用。基于先进激光的诊断技术处于燃烧研究的前沿，并提供非侵入式测量技术来解决燃烧环境中的多标量和矢量过程。特别是粒子图像测速技术（PIV）和OH平面激光诱导荧光（PLIF）的领先技术，已被结合起来调查的重要的湍流燃烧的化学耦合。 以前的研究结果在明火配置提供了显着的贡献的理解的间接火焰的相互作用，特别是在关于局部火焰熄灭。虽然以前的研究已经被激发的应用，如SI发动机，所有以前的实验已被限制到明火环境。为此，本提案的主题是开发高速PIV和OH PLIF技术来测量流场和火焰前缘特性，这些特性表征光学SI发动机中的火焰发展和局部火焰熄灭。所提出的测量活动预计将提供显着的努力，以改善燃烧性能，实现下一代喷射和燃烧策略的可行性，并提供有价值的数据集解决湍流火焰发展的SI发动机，帮助开发预测性IC发动机模拟用于进一步的燃烧和发动机的发展。

With increasing energy and environmental concerns, there is an evident need to improve fuel economy and reduce emissions from internal combustion (IC) engines. There is an evident need to resolve turbulent-chemistry interactions of developing flame fronts in spark-ignition (SI) engines to better understand and improve combustion performance in IC engines. Advanced laser based diagnostic techniques are at the leading edge of combustion research and provide non-intrusive measurement techniques to resolve multi scalar and vector processes within combustion environments. In particular particle image velocimetry (PIV) and OH planar laser induced fluorescence (PLIF) are among the leading techniques that have been combined to investigate the important turbulence-chemistry coupling with turbulent combustion. Previous findings within open flame configurations have provided notable contributions to the understanding of turbulent-flame interaction, particularly in regards to local flame extinction. Although previous studies have been motivated by applications such as the SI engine, all previous experiments have been limited to open flame environments. To this end, the subject of this proposal is to develop high-speed PIV and OH PLIF techniques to measure flow field and flame front properties that characterize flame development and local flame extinction in an optical SI engine. The proposed measurement campaigns are anticipated to provide notable efforts to improve combustion performance, realize the feasibility of next generation injection and combustion strategies, and provide valuable data set resolving turbulent flame development in SI engines that aid in the development of predictive IC engine simulations used for further combustion and engine development.