Abstract
One of the methods to reduce the engine exhaust emission is to use CCC. To obtain the maximum conversion efficiency in CCC, the exhaust gas should be uniformly distributed across the frontal area of catalytic substrate and the engine should be operated close to the stoichiometric air/fuel ratio through the use of an oxygen sensor in the exhaust system. A theoretical and computational study of three-dimensional unsteady compressible non-reacting flow in three kinds of exhaust manifold and CCC system was performed to understand the flow characteristics and to estimate the effects of the geometry change. Also, in each case, proper oxygen sensor location where the exhaust gas can be efficiently measured is proposed.