Turbocharged spark-ignition engine performance prediction in various inlet charged air temperatures fueled with gasoline–ethanol blends

Abstract

In this research, the effect of alternative fuels and the inlet charged air temperature is numerically investigated on the performance of a turbocharged spark-ignition engine. For this purpose, a one-dimensional engine and turbocharger model is created in an engine simulation and performance analysis software and validated with former experimental results. Then, the model is run with four fuel types, including two gasoline types with different octane numbers and two ethanol–gasoline blend fuels—E25 and E85. In each case, the inlet charged air temperature is changed from cold to hot condition and performance characteristics such as the spark advance timing, brake torque, brake-specific fuel consumption and thermal efficiency, emissions and the ignition delay and combustion duration are obtained from simulation results. The results illustrate that by decreasing the inlet charged air temperature, the spark timing is more advanced due to less knock and the brake torque increases. Also, the brake-specific fuel consumption and the brake NOx and CO2 decrease and thermal efficiency increases in all fuel types. The results also demonstrate that in higher ethanol percent in blend fuels, all engine performance characteristics improve except brake-specific fuel consumption; as changing the fuel at constant fuel-to-air equivalence ratio from E25 to E85 in various revolutions per minute causes a 5.8% increase in the brake torque, 1.06% increase in the thermal efficiency, 43% and 3.9% decrease in the brake NOx and CO2 and 5.8 °CA decrease in the combustion duration, on average; while the brake-specific fuel consumption and the peak pressure increase 29% and 20%, respectively.

Critical review on recent progress of ethanol fuelled flex‐fuel engine characteristics

“…Also, it causes the retardation of spark time that produces less power with higher BSFC. 96 In contrast to the effect of intake air temperature, a significant improvement in BMEP, BSFC, and BTE are observed for ethanol blends when manifold absolute pressure (MAP) increases due to the extended limit of knocking. 101 In most studies, the BTE of FFE running on ethanol blends is higher, while BP and SFC are lowered with the increase of lambda.…”

“…Particularly, the ID is increased with a decrease in inlet air temperature, due to prolonged chemical reaction time and tends to mitigate the knock. Also, there is no significant change in CD with ethanol quantity 96 . Ultimately, lambda (λ) plays a significant role in the combustion process of FFE, and the most of research emphasis optimizing the lambda range of FFE in stoichiometric and lean conditions 110 .…”

“…The torque and BTE of FFE are reduced with the increase in intake air temperature, as a result of lower air density and lesser mass of air entering into the combustion chamber, which leads to injecting less quantity of fuel to maintain constant lambda. Also, it causes the retardation of spark time that produces less power with higher BSFC 96 . In contrast to the effect of intake air temperature, a significant improvement in BMEP, BSFC, and BTE are observed for ethanol blends when manifold absolute pressure (MAP) increases due to the extended limit of knocking 101 .…”

“…The increase of inlet air temperature with ethanol blends in FFE shows a positive impact on combustion and a negative impact on emissions. Consequently, NO X , CO, and CO 2 are increased with the rise of intake air temperature due to lower efficiency and power 96 . Similarly, the increment of MAP results in higher PN because it requires a large quantity of fuel to maintain the λ .…”

“…Also, there is no significant change in CD with ethanol quantity. 96 Ultimately, lambda (λ) plays a significant role in the combustion process of FFE, and the most of research emphasis optimizing the lambda range of FFE in stoichiometric and lean conditions. 110 As increasing the lambda in FFE, the start of combustion tends to occur at lower temperatures with minimal energy and flame propagation speed.…”