RETRACTION: Experimental investigation of the influence of combustion chambers and compression ratio on the performance and emission characteristics of diesel engine (Retraction of August, 2020)

The present experimental study explores the effects of compression ratio (16:1, 17:1, and 18:1) and combustion chambers, namely, hemispherical combustion chamber (HCC) and toroidal combustion chamber (TCC), on a direct injection compression-ignition engine behavior. The test engine was operated at a constant speed of 1500 RPM with exhaust gas recirculation (EGR). With an increased compression ratio of the engine, TCC piston geometry has shown better improvement in brake thermal efficiency, and carbon monoxide (CO) and hydrocarbon (HC) emissions than HCC. However, a slight penalty in NOx emission was observed with increasing compression ratio and TCC piston geometry. In-cylinder peak pressure, net heat release rate and rate of pressure rise (ROPR) were increased significantly with increasing compression ratio and the use of TCC geometry. It is concluded that the simultaneous modification of piston geometry and the compression ratio is a promising option for better performance and lower emission behavior of the engine.