Effect of combustion chamber geometry on performance, combustion, and emission of direct injection diesel engine with ethanol-diesel blend

Abstract

In the present paper, the effect of combustion chamber geometry on performance, combustion and emissions of ethanol-diesel blend operated in direct injection Diesel engine is discussed. The main air motions are generated in the cylinder by the intake - induced swirl, the piston motion, and its geometry. The piston bowl is modified from traditional hemispherical combustion chamber to the toroidal (re-en-trant) combustion chamber and operated with Neat diesel and 40% ethanol diesel blend to improve better evaporation and mixing during the compression stroke on a single cylinder Diesel engine. It is found that the toroidal combustion chamber creates better turbulence, squish, and swirl at high compression ratios of 19.5:1 compared to that of traditional one. Further, the combustion is significantly enhanced due to increased swirl. It is concluded that the brake thermal efficiency for toroidal combustion chamber is 33% and the peak pressure in the cylinder as well as peak heat release rate is also increased. Further, it is also concluded that 60% of CO emission, 20% of HC emission, 40% of NOx emission, and 90% in smoke emissions were reduced for toroidal combustion chamber, compared to that of hemispherical combustion chamber.