Experimental Investigation of New Combustion Chamber Geometry Modification on Engine Performance, Emission, and Cylinder Liner Microstructure for a Diesel Engine

Emission values have been limited and some levels must be compatible with human health and the environment. One of the most effective ways to achieve these levels is effective piston bowl geometry. The aim of designing the new combustion chamber (NCC) was to provide a multiaxial distribution of the fuel in the bowl. In the study, the new combustion chamber was compared with the standard combustion chamber (SCC). Both chambers were fitted to the engine and the performance analysis was tested at different operation conditions. Then, 100-h tests were carried out to evaluate the effect of the piston bowl geometry on the surface of the cylinder liner by analyzing its microstructure. From the obtained results, the new combustion chamber geometry reduced HC, CO, and soot emissions while NO emissions slightly increased compared to the standard combustion chamber. It decreased brake-specific fuel consumption values by 4%, 5.53%, 7.02%, 6.4%, 5.55%, and 5.18% for 1700, 1800, 1900, 2000, 2100, and 2200 rpm, respectively. Torque values increased at all engine speeds. When the cylinder liners were evaluated as a result of long-term endurance, there were clearly fewer abrasive wear lines on the cylinder liners of NCC compared to SCC.