Hydraulic modelling of a catalytic converter for pollutant reduction in atmosphere

Air pollution caused by cars is a major contributor to the greenhouse effect, making it an issue of widespread concern. End-of-combustion of an engine produces pollutants such carbon monoxide (CO), oxides of nitrogen (NOx), oxides of sulphur (SOx), particulate particles and unburned hydrocarbons (HC). The environment, air quality, and human health are all negatively affected by these contaminants. A catalytic converter is a pollution control device for every fuel-operated automobile exhaust system. Increasingly low emission standards and automobile space constraints necessitate optimizing the device geometry. The uniformity index parameter mainly judges a catalytic converter’s smooth working and operational life. In the present study, 16 catalytic converter geometry designs are investigated. Their effects on exhaust flow distribution, i.e., uniformity index, pressure drop, and peak pressure at monolith substrate entry, are identified and visualized through contour plots. A finite volume approach is used to study hydraulic diffusion inside the device with the help of the ANSYS Fluent CFD package. Two-dimensional axisymmetric CFD simulations identify optimum design parameters among the considered geometries. The design of diffuser geometry is crucial in maintaining a uniform flow across monolith honeycomb structures.