Thermal Front Propagation of Fast Igniting Catalytic Converters

为了更好地理解控制这些现象的因素，我们将从理论和实验上研究催化转化器中热锋的着火和传播问题。利用非线性动力学和分叉理论进行的初步理论分析将扩展到对更复杂模型的分析。在实验上，宏观热波的传播将通过对无载体模型衬底的红外热成像研究、对负载型模型催化剂的研究以及对催化转化器截面的研究来研究。此外，还将对两个反应点之间的连通问题(单个催化剂颗粒之间的连通)进行类似的实验研究。最后，在初步分析的基础上，预测了一种新的径向催化转化器设计，该转化器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延迟充分有效地运行，这使得具有最小点火延迟和快速热前沿传播的催化转化器的开发变得非常重要。因此，该计划的一个主要目标是发展对关键现象(基本机制)的了解，这将导致设计出更高效的快速点火催化转化器，而不需要繁琐的外部加热源(另一种“修复”冷启动排放问题的方法)。

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.