The Research Of Vector Structure Of Auto Catalytic Converter And Analysis Of Flow Characteristics

Catalytic converter is an assemble of efficiently controlling the poisonous emissions from internal combustion engine. In order to meet the more and more strict emission standards, the catalytic converter not only have a high conversion efficiency, a long durability and low light-off temperature and good flow quality. The complicated flow and heat and mass transferred in the catalytic converter are the most important factors. The asymmetry of flow begets vortex and the separation of airflow which is the cause of pressure losses and it contributes the asymmetry of temperature. Catalyzes become invalidation easily in the areas where the temperature is too high, but in the low temperature place, it can not obtain full use, causes the overall conversion rate to reduce. The temperature distribution non-uniformity can cause the carrier radial direction gradient of temperature to increase, produces the thermal load surface, causes the carrier to have the thermal deformation and the damage. Thus, it needs to know the liquidity of inner flowage and ameliorate the structure of catalytic transformer according to ideal speed, Achieves the optimized design the goal.Now, the mostly important method in study flows in catalytic converter is to concentrate the change of the structure of expansion pipe and shrinking pipe, the size of expansion angle, the position of the vector catalytic converter and analysis of the internal flow characteristics and pressure loss. Although the research technology tend to be mature, the practical application and the formulation of commercial products are difficult.The actuality research of the internal flow characteristics is proceeded by changing the catalytic converter vector of the end structure, and establishing a mathematical model, meshing and setting reasonable boundary conditions. Use software "CFX" to do the numerical simulation of the flow quality of the catalytic converter. The ball-shaped crown, hemispherical and Semi-spherical wind vector end of internal the flow field calculation and post-processing, analysis catalytic converter flow characteristics. The comparison with the liquidity of the perpendicularity surface indicates that the flow quality of ball-end type is better than perpendicularity-end type, the flow quality of the catalytic transformer of half-ellipse-end type is the best among these types.