Experimental and Numerical Prediction of the Pressure Drop Reduction of Catalytic Converter under Various Mass Flow Rate of Exhaust Gas for a Naturally Aspirated Diesel Engine

摘要

Nowadays, Diesel emission control strategies are stringent across the globe which caused the rise in need of diesel after treat treatment devices that are more reliable and efficient. The optimized design of the catalytic converter aids in the durability of the product as well as the improvement in efficient operation of the Indian driving cycle. By changing the convergent and divergent cone angles of the catalytic converter, the consequential decrease in pressure drop leads to efficient flow of exhaust gases. The purpose of this study is to design, test, and analyse the catalytic converter in order to reduce the pressure drop in the exhaust system of a naturally aspirated diesel engine using both experimental and CFD techniques. In this study, a Diesel Oxidation Catalyst Catalytic Converter is investigated. For numerical analysis, ANSYS Fluent is used. Validation is done on baseline Catalytic converter pressure drop results obtained both numerically and experimentally for various speeds conditions and it is found that a reasonably good agreement exists. From the analytical calculations, Catalytic converter diameter, length and Cone angle are selected so as to have maximum pressure drop reduction. The modified inlet and outlet cone angles in catalytic converter chosen are 20°, 22°, 26°, and 28° and the porosity value is 0.826 with square shaped pores in monolith. The Cone angle of 26° gives more reduction in pressure drop of 1.7499KPa, which is less than the baseline pressure drop value of 1.85699 KPa. This leads to 7% overall pressure drop as compared to the different cone angle results. It could be concluded that the inlet and outlet cone angles must be in 26° to yield best flow with reduced pressure drop across the catalytic converter for the selected engine configuration and operating conditions when the porosity is 0.826 with the shape of square monolith.