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

随着人们对能源和环境问题的日益关注，提高燃油经济性和减少内燃机（IC）排放的需求日益明显。为了更好地理解和提高内燃机的燃烧性能，有必要解决火花点火发动机中发展中的火焰前缘的湍流化学相互作用。先进的基于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（PIV）和OH平面激光诱导荧光（PLIF）是研究湍流燃烧中重要的湍流化学耦合的领先技术。以前在明火结构中的发现为理解湍流-火焰相互作用，特别是局部火焰熄灭方面提供了显着的贡献。虽然以前的研究是由SI引擎等应用驱动的，但所有以前的实验都局限于明火环境。为此，本提案的主题是开发高速PIV和OH PLIF技术，以测量光学SI引擎中表征火焰发展和局部火焰熄灭的流场和火焰前缘特性。预计所提出的测量活动将为改善燃烧性能，实现下一代喷射和燃烧策略的可行性提供显著的努力，并提供有价值的数据集，解决SI发动机中湍流火焰的发展，帮助开发用于进一步燃烧和发动机开发的预测IC发动机模拟。

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.