No abstract

This study was carried out to predict the impact of injection timing and injection duration on engine brake power and Nitrogen Oxides emissions in a diesel engine using biofuel Soya Methyl Ester (SME). Predictions were accomplished at three different injection timings 10˚, 5˚ Crank Angle (CA) before Top Dead Center (bTDC) and 0˚ CA at Top Dead Center (TDC) and four injection durations 20˚, 25˚, 30˚, 35˚ CA. The study was conducted using a simulation software (Diesel-RK). The predicted results showed that the powers produced by all the setups of the different injection timings are almost equal, but they differ in injection durations, e.g. the power at setup (10˚ CA-bTDC) duration 20˚ CA and 2500 rpm equal to 52 kW, at setup (5˚ CA-bTDC) duration 25˚ CA and same engine speed the power is equal to 51 kW, and at setup (0˚ CA-TDC) durations 30˚ the power is equal to 51 kW. The power in all setups are decreased as the injection duration increased, e.g. at setup 0˚ CA TDC durations 25˚, 35˚, and 40˚ CA and at 4000 rpm, the brake powers are equal 71, 65, and 59 kW respectively, thus the reduction percentages are 9% and 17% when compared to the 25˚ injection duration. The nitrogen oxides emissions decreased as the injection duration is increased, e.g. the emissions at setup (10˚ CA-bTDC) durations 25˚, 30˚, and 40˚ CA and at 2500 rpm are equal 852, 589, 293 ppm respectively, the reduction percentages are 30% and 72%. The variations of injection timing and injection duration have taken a weighty influence on engine performance and emissions. The results are considered as a novelty in the field of using pure biofuel Soya Methyl Ester in diesel engine according to our information.