Fundamental studies of auto-ignition and combustion in a low-emission natural gas engine

众所周知，天然气（NG）在常规柴油发动机操作条件下不会自燃。热表面点火（HSI）为这一问题提供了一个实用的解决方案。因此，所提出的研究计划的目标是双重的;在最基本的水平，研究的目的是发展一个更好的理解卷吸和混合的作用，对湍流气体燃料射流的点火和燃烧的冲击在热表面上。在应用层面上，本研究的目标是开发一种用于直喷式天然气燃料柴油循环发动机的耐用热表面点火器，并将使用甲烷作为控制燃料进行一系列基于控制台的实验、光学访问发动机实验和数值模拟。建议的研究计划将提供一个更好的基本了解的要求，在HSI直喷天然气发动机的可靠点火和燃烧。在这项研究中获得的数据将使改进的点火和燃烧的数值模型，以开发这类发动机，因此，直接和间接，促进优化NG HSI柴油循环发动机的发展。与传统的柴油和火花点火发动机相比，优化的发动机将提供显著的二氧化碳减排效益，并降低其他污染物的排放水平。与直接喷射NG发动机的双燃料“引燃”操作相反，HSI方法容易适用于中型和轻型应用。因此，直接喷射的NG HSI发动机将非常适合于为未来的燃油效率高的混合动力车辆提供动力。

It is well known that natural gas (NG) does not auto-ignite under conventional diesel engine operating conditions. Hot surface ignition (HSI) provides a practical solution to this problem. Therefore, the objectives of the proposed research program are twofold; at the most fundamental level, the research is intended to develop an improved understanding of the role of entrainment and mixing on the ignition and combustion of turbulent gaseous fuel jets impinging on a hot surface. At an applied level, the objective of the research is to develop a robust hot-surface igniter for use in a direct-injected, natural gas fuelled, diesel cycle engines.An integrated series of controlled rig-based experiments, optically-accessed engine experiments, and numerical simulations will be performed using methane as a control fuel. The proposed research program will provide a better fundamental understanding of the requirements for reliable ignition and combustion in a HSI direct-injected NG engine. The data acquired during this study will enable improved numerical models of ignition and combustion to be developed for this class of engine and will thus, both directly and indirectly, facilitate the development of an optimized NG HSI diesel-cycle engine. The optimized engine will offer substantial CO2 reduction benefits and reduced levels of other pollutants emissions when compared to conventional diesel and spark-ignited engines. In contrast to the duel-fuel 'pilot-ignited' operation of direct-injection NG engines, the HSI approach is readily applicable to medium and light-duty applications. Accordingly, direct-injected NG HSI engines will be well suited to power future, fuel-efficient hybrid vehicles.