Experimental Study on Performance, Combustion and Emissions of Diesel Engine with Re-entrant Combustion Chamber of Aluminum Alloy

Abstract

Internal combustion engines have been in use for more than a century and have undergone tremendous changes in their design, materials used and operating characteristics. Diesel engine is the most efficient type of internal combustion engines. In past few decades research efforts have been focused largely on better engine design from the perspective of reducing pollutants emission without sacrificing performance and fuel economy. Gas motion inside the engine cylinder, which depends on combustion chamber geometry is highly influences the performance of any internal combustion engine. Hence an attempt is made to study the performance, combustion parameters and emission particulates of diesel engine using different designs of combustion chambers of Aluminum alloy, in order to enhance the air swirl. Experiments are conducted on four stroke single cylinder water cooled diesel Engine at constant speed of 1500 rpm at different loads with hemispherical, toroidal and re-entrant toroidal geometries of the combustion chambers. The effect of varied piston bowl geometry on performance & combustion parameters viz. brake thermal efficiency (BTE), Brake specific fuel consumption (BSFC), exhaust gas temperature (EGT), heat release rate (HRR) & cylinder pressure and emission particulates have been investigated and presented in this paper. Results suggest that re-entrant piston bowl geometry has significant impact on performance, combustion characteristics and emission particulates inside the cylinder with varied piston bowl geometry shows that the squish flow effects the turbulence near the TDC during compression stroke. However, there is slight increase in particulates of NOx particulates due to increase in combustion temperature with enhanced air swirl with varied piston bowl geometry.