The Research On Gas Flow In Catalytic Conversion In Motorcycle And The Optimization Of Its Structure Based On Nanometer Reducer

In recent years the volume of motorcycle possess has increased quickly with rapid development of motorcycle industry in our country. The pollution of the emission of motorcycle has received more and more concern from the society. The limits of control emission have become more and more strict. At present, there are many methods to purify the exhaust gas, for example, the improvement of carburetor structure, the adoption of electricity fuel injection system, catalytic converter technology, electric-motorcycle. The catalytic converter technology is the main measure to purify the exhaust gas. The precious metal three way catalyst that is composed of Pt, Pd and Rh has very high efficiency to transform the poisonous gas of CO, CH and NO_x. But the precious metal is short and precious, so they are not suitable for the inexpensive motorcycles.At the same time, many reports show that the rare-earth metal is extremely lively and its catalytic effect is good with low cost.With rare-earth oxide compound and Mn(NO₃)₂ used as raw material, nanometer rare-earth compound catalyst was prepared by sol-gel and vacuum drying technology and experiments shew that its catalytic activity was good. The catalytic effect was not only related with the ingredient of catalyst but also related with the inner flowing instance. So the article used the CFD software FLUENT to analyze the inner flowing instance of the WuYang 125 style exhaust pipe Then the best install place was confirmed.The simulation of catalytic converter shew that the cone angle and the length of the ceramic carrier's front and behind cavity could effect the catalyzed transformation.The structure was optimized by changing the cone angle and the length of the ceramic carrier's front and behind cavity.