Numerical Analysis on Cone Length and its Effect on Performance of an Automotive Catalytic Converter

Abstract

Internal combustion engines are one of the major contributors of air pollution. Exhaust gas from these engines contains HC, CO, NOx, PM and smoke which are the harmful pollutants to humans as well as to the environment. The stringent norms enforced by governments has necessitated in improving the after-treatment processes of these exhaust gas. A three-way catalytic converter is one of the most effective devices in treating the HC, CO and NOx pollutants into non-toxic gases. In this paper, numerical investigation is carried out by using commercial CFD code, ANSYS Fluent to analyse the effect of cone length on the conversion efficiency of the Catalytic Converter (CC). Pressure drop, back pressure and temperature are the parameters which are monitored in this study. The cone length of the CC is varied from 70mm to 90mm in steps of 10mm. All the CCs are analysed for identical test conditions. It is observed that temperature and pressure showed an appreciable decrease with increase in cone length to 90mm. On the other hand, velocity increases with increase in cone length to 90mm. A lower pressure drop and temperature is observed for the CC with cone length of 90mm. As conversion efficiency of the CC is dependent on the lower pressure drop, lesser back pressure and lower temperature, the CC with cone length of 90mm is found to be the apt choice.