Decomposition kinetics of organic fluorescence tracers under IC-engine-like conditions:Shock-tube experiments and kinetic modeling

内燃机的创新概念，如充量压缩点火（HCCI），需要在点火前详细了解气体混合物。在过去的二十年里，基于激光诱导荧光（LIF）的示踪剂和荧光燃料化合物用于燃料浓度可视化已经发展成为一种重要的工程工具，并已被证明在火花点火（SI）发动机研究中不可或缺。非常希望将这些技术转移到HCCI或柴油环境中。然而，示踪剂在高温下表现出有限的稳定性，并且在预点火阶段与基础燃料一起部分分解。到目前为止，这阻碍了对观察到的荧光信号的解释，但另一方面，将允许提取关于预点火化学的信息，这对于进一步深入了解自动点火过程是有价值的。另一方面，示踪剂对基础燃料点火特性的潜在影响在过去大多被忽略。我们建议改善的基本基础，定量，多维示踪LIF测量的燃料混合和预点火化学的观察。这将通过激波管实验和动力学模型相结合来完成。该项目的目标是：（a）评价示踪剂分解动力学，以便能够在自燃环境中进行定量测量;（B）调查燃料/示踪剂混合物的点火情况，以确保发动机性能不受示踪剂影响;（c）研究高温下的示踪剂光谱学，以便能够对信号进行定量解释。这项工作将在IVG，杜伊斯堡-埃森大学（实验）和ITT，卡尔斯鲁厄大学（建模）的合作下完成。

Innovative concepts for internal combustion engines like homogeneous-charge compression ignition (HCCI) require a detailed knowledge about the gas mixture prior to ignition. The use of tracers and fluorescing fuel compounds for fuel-concentration visualization based on laserinduced fluorescence (LIF) has grown to an important engineering tool over the last two decades and has proven indispensable in SI (spark-ignition) engine research. It is highly desirable to transfer these techniques to HCCI or Diesel environments. However, the tracers exhibit limited stability at high temperature and partially decompose together with the base fuel in the pre-ignition phase. This up to now hinders the interpretation of the observed fluorescence signals, but on the other hand would allow to extract information about pre-ignition chemistry that would be valuable for further insight into the auto ignition process. On the other hand, the potential influence of the tracer on the ignition characteristics of the base fuel has mostly been ignored in the past. We propose to improve the fundamental basis for quantitative, multi-dimensional tracer-LIF measurements for the observation of fuel mixing and pre-ignition chemistry. This will be done by a combination of shock-tube experiments and kinetic modeling. The objectives of the project are (a) to evaluate the tracer decomposition kinetics in order to enable quantitative measurements in auto-igniting environments (b) to investigate ignition of fuel/tracer mixtures in order to ensure conditions where the engine performance is not affected by the tracer, (c) to study the tracer spectroscopy at high temperatures to allow for quantitative signal interpretation. The work will be done in a collaboration of IVG, Universität Duisburg-Essen (experiments) and ITT, Universität Karlsruhe (modeling).