Optimum diffuser geometry for the automotive catalytic converter

Abstract

Catalytic converters have become an integral part of modern cars as they provide excellent control on pollutants but also lead to reduction in the overall efficiency of the engine. In the present study, the geometry of the inlet header, which is primarily a diffuser, has been optimized using Computational Fluid Dynamics (CFD) for minimizing the pressure loss. It has been found that the optimum design of the diffuser is the one having moderate diffuser half angle for most part of its length and then gradual but steeper diffusion in the later part along with a smooth wall curvature.