Modeling and Simulation of
Catalytic Converter Flow

The major undesirable chemical species that constitute the main exhaust emissions produced by spark ignition engines are hydrocarbons (HC's), carbon monoxide (CO) and nitrogen oxides (NOx). The catalytic converter is the most important device for emission control from spark-ignition engines. Several concurrent physical processes such as convective heat transfer, gas phase chemical reactions, surface reactions, flow oscillations, water vapor condensation and diffusion add to the system's complexity. Under cold start conditions the catalytic converter does not become operational during the first two minutes of operation, allowing a significant fraction of the overall pollutants to be emitted. We have developed a multi-dimensional model to examine these phenomena and suggest new material-dependent designs to improve the conversion efficiency of the device and cold start performance.

Monolith surface temperature distriution at different times.

Reference:
"Modeling and Simulation of Transient Thermal and Conversion Characteristics for Catalytic Converters," Lacin, F. and Zhuang, M., SAE 2000-01-0209 (2000).