摘要:A theoretical investigation using RSM statistical technique on the relative change of emissions of a four-stroke, direct injection, water-cooled, 4-stroke, diesel engine with variable stroke length was carried out. The performance parameters were studied over wide range of speeds (1000 - 3000 RPM at an increment of 500 RPM) and stroke lengths (130 mm to 210mm at an increment of 20mm). The compression ratio was kept constant by adjusting the piston bowl volume. It was found within the range of stroke length studied, that larger stroke lengths are favorable for lower NOx and specific CO2 emissions. This is due to the lower availability of Oxygen. As for specific PM and BSN, the shorter the stroke length the lower the levels. This is attributed to improved engine charging efficiency, hence, better availability of oxygen.