Experimental and numerical analysis of flow through catalytic converters for original part and WALKER's replacement using reverse engineering and CFD

Abstract

The paper describes results of experiments and CFD simulation for an original catalytic converter part and WALKER's replacement. Pressure drop was measured for catalysts, which influences on exhaust backpressure, an important parameter affecting the engine power, fuel consumption, emission of harmful gases and wear components. First the pressure drops was examined in the original catalyst and in prototypes of WALKER's. The prototypes differed in that their monoliths had different lengths, density of channels and contents of precious metals (PGM). In the next stage reverse engineering was applied, which included laser scanning of parts and then processing the point clouds in Leios2 program. Recreated 3D geometry of catalysts in Catia v5 program was prepared for computational fluid dynamics. For all studied cases the measured data were used to calculate coefficients of porous media model i.e. viscous and inertial resistances, which were used in the Ansys Fluent program. Static pressure drops on the monoliths were then predicted by the CFD model for different gas mass flow rates through the catalysts. Exhaust velocities and flow uniformity were also analysed. Comparison of the results for all parts allowed for stating, which prototype is better and which has operating parameters comparable to the original part.