Simulation Of Light-off Performance And Multi-structure Flow Field Of Catalytic Converter

As one of the most widely used methods of vehicle exhaust post treatment, the three-way catalytic converter (TWC) plays a significant role in purifying vehicle exhaust and improving air quality. Along with the development of world economy, the environment quality is getting worse and worse and the natural resources become less and less, the exhaust treatment regulations are also becoming tough than before, all of above have raised a more rigid requirement to the performance of TWC. The TWC not only should has high converting efficiency but also has enough long life span and high stability, the negative influence TWC put to the whole exhausting system should be as small as possible. The key aspects of modern TWC research are improving the cold-starting converting efficiency and optimizing inner flowing field of TWC.The traditional research method of TWC was experiment, it could provide the necessary information to research of TWC, but it could not give certain information of gas-solid heat transfor,mass transfer,chemical reaction and gas flowing, besides, the experiment method had big cost and long period. Along with the development of computer technology and the mathematical model, the research method of numerical simulation became more more popular in the research of TWC, it was very helpful on improving distribution of velocity,decreacing pressure loss,improving converting efficiency,decreacing heat stress in carrier and lengthening life span, it also effectively complemented the limitation of traditional experiment method, the method of combination of experiment and numerical simulation had promoted the process of TWC research.This paper had studied the inner flow field of TWC with different structural parameters, it built the mathematical model of the inner flow field of TWC and carried on the numerical simulation of inner flow field of TWC with multi-structure parameters through using the CFD software-FLUENT, some regulations about velocity distribution on carrier and pressure loss between inlet and outlet with different structural parameters were got, some rational proposals were also put forward aiming to optimize the flow field. In addition, the paper also studied the cold-starting performance and the big significance to improve the converting efficiency in cold-starting period, it built the mathematical model of heat transfer,mass transfer and chemical reactions inside TWC, carried on the mumerical simulation of the light-off performance of TWC and some regulations about gas consistency field,temperature field and exhaust converting efficiency inside TWC were got, the simulation results effectively reflected the chemical process inside TWC, the numerical simulation with CFD would play an very important role in the process of TWC research.