Effect of piston bowl geometry and different injection pressure on the performance, emission and combustion characteristics of diesel engine using biodiesel blend

The shape of the piston cavity, variable injection pressure and variable compression ratio are main input parameters to give better atomization of fuels and high swirling induction that improves the Diesel engine performance, combustion, and emissions characteristics. In this study, the engine test was carried out to improve the combustion, performance, and emissions with the use of two different pistons namely hemispherical shaped piston (standard engine), and toroidal cavity piston with varied injection pressures in a single-cylinder direct injection Diesel engine using 25% of corn oil methyl ester-diesel blend (COME25). Initially, the piston bowl was modified to toroidal combustion chamber with tangential cut on circumference of the piston crown in a standard piston of hemispherical type combustion chamber. The engine speed, compression ratio, and injection timing were kept constant and the results of toroidal combustion chamber compared with base engine piston of hemispherical combustion chamber using diesel and COME25 fuel. The results showed that the toroidal combustion chamber has improved performance, combustion and emissions with the exception of NOx emissions