Detailed chemistry investigation for model development for engine control

该项目旨在为研究单位提供基本的化学知识。它致力于分析的物种配置文件所需的发展和关键检查的反应动力学模型的发动机项目，然后将被纳入发动机控制程序。这些分析将主要在低温条件下的流动反应器中进行，使用替代燃料异辛烷（用于TP 3中的GCAI燃烧）和正庚烷（用于TP 4中的PCCI条件）。该项目侧重于相关反应动力学的几个方面。对于GCAI条件，一个重要的方面是水添加对点火特性的影响。将研究在不同条件下对异辛烷进行可变水添加的参数场的影响，目的是了解水添加对低温范围内反应动力学的基本机制，并将此知识转移到模型开发中。计划中的调查是在这些条件下处理新的领域。因此，分析将支持选定的研究条件下的稳定预混扁平低压火焰。对于在PCCI域的模型开发，详细调查的烟灰前体物种的形成，在该制度高达约四个芳环，优先在低温条件下的计划。虽然朝向第一芳环的反应被认为是很好理解的，但是在分子前体相中直到3-4个芳环的形成动力学的基本理解中仍然存在很大的差距。例如通过这种多环芳族化合物的二聚作用而向第一烟灰颗粒成核延伸的这一阶段在从燃料分子到初始颗粒的反应序列中具有突出的重要性，因此，关于这些过程的基本知识对于TP 4的模型开发具有重要影响。因此，这些调查将部分支持的非预混火焰中的非常富燃料区的分析。此外，对于两个发动机燃烧项目，了解排气成分对反应动力学机制的影响是有意义的。根据对加水影响的研究，计划进行选定的调查，以解决这些影响。将使用该小组具有长期经验的质谱技术的不同变体，在所有设置中确定作为反应条件函数的物质概况。这些技术将得到气相色谱法和激光技术的支持，用于温度测量。

The project serves to provide the fundamental chemical knowledge for the Research Unit. It is devoted to the analysis of species profiles that are needed for the development and critical examination of reaction kinetic models for the engine projects that will then be incorporated into the engine control routines. Theses analyses will be mainly conducted in a flow reactor under low-temperature conditions using the surrogate fuels iso-octane (for the GCAI combustion in TP3) and n-heptane (for the PCCI conditions in TP4). The project focuses on several aspects of the relevant reaction kinetics. For GCAI conditions, an important aspect is the influence of water addition on the ignition characteristics. The effects of variable water addition to iso-octane will be studied for a parameter field at different conditions with the aim to understand the fundamental mechanisms of water addition on the reaction kinetics in the low-temperature regime and to transfer this knowledge into the model development. The planned investigations are addressing new territory under these conditions. The analysis will thus be supported by selected studies under the stable conditions of premixed flat low-pressure flames. For the model development in the PCCI domain, detailed investigations of the formation of soot precursor species in the regime up to about four aromatic rings, preferentially under low-temperature conditions are planned. While reactions towards the first aromatic ring are thought to be well understood, large gaps remain in the fundamental understanding of the formation kinetics in the molecular precursor phase up to 3-4 aromatic rings. This phase that extends towards the first soot particle nucleation, for example via dimerization of such polycyclic aromatic compounds, is of eminent importance in the reaction sequences from the fuel molecule to the incipient particle, and consequentially, fundamental knowledge on these processes is of important influence for the model development for TP4. These investigations will thus be supported in part by analyses of very fuel-rich zones in a non-premixed flame. Furthermore, for both engine combustion projects, it is of interest to understand the influence of exhaust components on the reaction kinetic mechanisms. Building upon the study of the effects of water addition, selected investigations are planned which address these effects. The determination of species profiles as a function of reaction conditions in all set-ups will be performed using different variants of mass spectrometric techniques, for which the group has long-standing experience. These techniques will be supported by gas chromatography as well as laser techniques for the temperature measurements.