Numerical investigation of different combustion chamber on flow, combustion characteristics and exhaust emissions

Abstract

This study includes numerical analysis of diesel engines with different bowl geometry. Numerical analyzes of the diesel engine with asymmetrical bowl geometry were performed in Ansys Forte software. In the study, four-stroke, air cooled, a single-cylinder and direct injection diesel engine were used. It has been tested where the maximum torque is obtained as the operating condition at 2000 rpm. According to the results obtained from the analyzes, the new combustion chamber system geometry provided a 40.3% reduction in soot emissions while NO emissions increased slightly with the 8-cavity bowl geometry created in the chamber compared to the standard combustion chamber system. Increasing air velocity, and turbulent kinetic energy values in the chamber affected the evaporation levels of the fuels. As a result, the improved mixture formation caused a decrease in incomplete combustion products (CO, HC and soot). The new combustion chamber system geometry according to standard combustion chamber system type, an increase of approximately 4.2% occurred in the calculated squish rates. It has been observed that the increase in the bowl surface area causes the combustion, and thus the temperature to spread over a larger area on the piston.