Dynamic Characteristics Simulation Of Gasoline Engine Manifold Catalytic Converter

Vehicle exhaust purification is the main technical measures to control theemissions, and exhaust manifold catalytic converter is an important part of the exhaustsystem. Because of increasingly stringent emissions regulations, the performance of themanifold catalytic converter has become increasingly demanding, more complexstructural design, structural become increasingly evident to the properties of themanifold catalytic converter.In order to evaluate the performance and provide a strong theoretical basis for thestructural design and modification of the manifold catalytic converter, finite elementmethod and larger commercial software ANSYS and Hyper Mesh are used for thefollowing areas of research and analysis of the manifold catalytic converter in thispaper.①Calculating the free and constraint mode of the manifold catalytic converter,achieved the natural frequencies and corresponding mode shapes of the free orconstraint mode. Then, analyze the vibration characteristics of the manifold catalyticconverter.②Studied on the three-dimensional flow field of the manifold catalytic converter,achieved the fluid velocity field, temperature field and pressure field. And analyze theflow uniformity index of the carrier inlet end in the catalytic converter part.③The thermal stress, safety factor and temperature of coupling field of gasolineengine manifold catalytic converter were calculated with the fluid-structure thermalinteraction. According to the calculation results, the thermal stress is excessive inentrance flange area. And it is easy to produce the stress concentration and is damagedeasily in this area. In addition, the thermal deformation is greater in the junction areabetween exhaust manifold and catalytic converter. So a further structure improvementmust be made in this paper.④Finally, the improved structure was presented according to the calculation results.And, the corresponding analysis and comparison show that the improved structure isbetter than the original structure in the highest temperature, the maximum thermalstresses and the safety factor.