Numerical Simulation For Working Process Of Vehicle Catalytic Converter

The technology of controlling vehicle emission is researched. Some deep studies, matching technology of engine for vehicle, emission performance of engine, working process of emission postprocessor, are investigated. It provides a technology basis of theoretic and testing research for the control of vehicle emission.In the fields of matching technology of engine for vehicle, the predicttive model based on vehicle running cycle of emission performance and economic feature is set up. It can deal with the match and optimization of vehicle, transmission and engine for the objective of improving the vehicle emission performance. The vehicle dynamics analysis software is developed. It can analyze the vehicle emission performance.During the research of emission performance for engine, calculating models for physics and chemical characteristic parameters of exhaust gas are set up. Especially, APR (Air Flew Ration) calculating model is derived based on the chemical analysis of burning process. It is suitable for all kind of fuels.Computer fluid dynamics (CFD) is adopted to simulate the flow fields of catalytic converter while researching the working process of emission postprocessor. The velocity field and pressure field of exhaust gas are obtained. Methods of structural optimization of catalytic converter for improving gas flow and conversion efficiency are proposed. Mathematical models of catalysis, heat and mass transfer in carrier are set up. The finite element software of simulating the working process of catalytic converter is developed. This, software can make the numerical simulation and testing research for catalyst converter during warm-up period. Loading patterns of catalyst in carrier are discussed. Two loading patterns, which cost are lower and can largely improve conversion characteristics of catalytic conyerter during warm-up period, are put forward.This thesis will be of great value of learning research and engineering apply in controlling vehicle emission. It can provide a basis and direction for the design and improvement of controlling system on vehicle emission.