Impact of Manifold Design on Flow Distribution of a Close-Coupled Catalytic Converter

Moving the catalytic converter closer to the engine reduces its light-off time. However, temperature and pulsating flow have a stronger impact on a close-coupled catalytic converter than an under-floor. For close-coupled architecture, manifold design may play a major role by affecting flow distribution. Consequently, emission performance and durability of thin-wall substrates can be affected.

The study being carried out aims at highlighting the impact of manifold design on flow distribution focusing on different manifold configurations. Flow distribution results in hot wire probe measurements. Temperature measurements support the results. Experiments are finally confronted with CFD predictions.

The results obtained give trends to design both close-coupled catalytic converter and manifold for better emission performance and resistance to erosion.