Thermal Front Propagation of Fast Igniting Catalytic Converters

为了更好地了解控制这些现象的因素，本文将对催化转化器中热锋的点火和传播问题进行理论和实验研究。利用非线性动力学和分岔理论的初步理论分析将扩展到更复杂模型的分析。实验上，宏观热波传播将通过红外热成像研究在无负载模型基板上的研究，在负载模型催化剂上的研究，以及在催化转化器部分的研究。此外，两个反应点之间的通信问题（单个催化剂颗粒之间的通信）将进行类似的实验研究。最后，在初步分析的基础上预测了一种新型径向催化转化器的设计，该设计在快速点火和热锋传播方面具有特别理想的特性。不断发展的汽车空气污染法规要求催化转化器在发动机启动后以最小的时间延迟达到完全有效运行，因此开发具有最小点火延迟和快速热锋传播的催化转化器非常重要。因此，该项目的一个主要目标是发展对关键现象（基本机制）的理解，这将导致设计更高效的快速点燃催化转换器，而无需繁重的外部加热源（“解决”冷启动排放问题的另一种方法）。

The problems of ignition and propagation of a thermal front in a catalytic converter will be studied theoretically and experimentally in order to gain a better understanding of the factors controlling these phenomena. A preliminary theoretical analysis utilizing non-linear dynamics and bifurcation theory will be extended to analysis of more complex models. Experimentally, macroscopic thermal wave propagation will be investigated via infrared thermography studies on unsupported model substrates, studies on supported model catalysts, and studies on a section of a catalytic converter. In addition, the issue of communication between two reactive spots (communications between individual catalyst particles) will be similarly experimentally investigated. Finally, a new radial catalytic converter design which is predicted on the basis of preliminary analysis to have particularly desirable characteristics as regards fast ignition and thermal front propagation will be studied further. Evolving air pollution regulations for automobiles have the effect of requiring that catalytic converters come up to full effective operation with a minimal time delay subsequent to engine startup, making the development of catalytic converters with minimal ignition delay and rapid thermal front propagation highly important. Accordingly, a major goal of this program is development of an understanding of the critical phenomena (fundamental mechanisms) which will lead to design of more efficient fast-igniting catalytic converters without the onerous requirement of external heating sources (an alternative approach to "fixing" the cold startup emissions problem.