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。它致力于物种概况的分析，这是需要的发展和反应动力学模型的发动机项目的关键检查，然后将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TP3中的GCAI燃烧）和正庚烷（用于TP4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，一个重要方面是加水对点火特性的影响。我们将在不同条件下的参数场中研究不同加水对异辛烷的影响，目的是了解加水对低温反应动力学的基本机制，并将这些知识转移到模型开发中。在这些条件下，计划中的调查正在探索新的领域。因此，在稳定的预混扁平低压火焰条件下的选择研究将支持分析。对于PCCI领域的模型开发，计划详细研究在大约四个芳香环的情况下，优先在低温条件下形成煤烟前体物种。虽然第一个芳环的反应被认为是很好的理解，但在分子前体相的形成动力学的基本理解上仍然存在很大的差距，直到3-4个芳环。这个阶段延伸到第一个烟灰颗粒成核，例如通过这种多环芳香族化合物的二聚化，在从燃料分子到初始颗粒的反应序列中是非常重要的，因此，关于这些过程的基础知识对TP4的模型开发具有重要影响。因此，这些研究将在一定程度上得到对非预混火焰中非常富燃料区域的分析的支持。此外，对于这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。在研究加水的影响的基础上，计划了一些针对这些影响的调查。在所有装置中，作为反应条件函数的物种概况的测定将使用不同变体的质谱技术进行，该小组在这方面有长期的经验。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.