Automotive Science and Engineering

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The effects of unleaded gasoline and unleaded gasoline–ethanol blends on engine performance and pollutant emissions were investigated experimentally in a single cylinder, four-stroke spark-ignition engine with variable engine speeds (2600–3500 rpm). Four different blends on a volume basis were applied. These are E0 (0% ethanol + 100% unleaded gasoline), E3 (3% ethanol + 97% unleaded gasoline), E7 (7% ethanol + 93% unleaded gasoline) and E10 (10% ethanol + 90% unleaded gasoline). Results of the engine test indicated that using ethanol–gasoline blended fuels improve output torque, power, volumetric efficiency and fuel consumption of the engine it was also noted that fuel consumption depends on the engine speed rather than the ethanol content for ethanol less than 10% blended ratio. CO and unburned hydrocarbons emissions decrease dramatically as a result of the leaning effect caused by the ethanol addition CO2 emission increases because of the improved combustion.

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Among human activities, motor vehicles play the most important role in air pollution. Air pollution has negative impacts on people and on the environment. In this paper the effect of oxygen-enriched air (20.8%, 21.8%, 22.8%, 23.8% and 24.8%) and different bioethanol-gasoline blends (zero, 5%, 10%, 15%, 20% and 25%) in different engine speeds (1000 rpm, 2000 rpm and 3000 rpm) on the amount of pollutants, particles, and fuel consumption were studied. To do so, a four-cylinder, four-stroke gasoline engine with Siemens fueling system was used. The results showed that when oxygen percentage in the inlet increased from 20.8% to 24.8%, the average amount of UHC, CO, fuel consumption and the number of fine and coarse particles decreased 126.75%, 11.25%, 17.02%, 77.37% and 243.25%, respectively, while the amount of CO2 and NOX increased 5.36% and 113.27%, respectively. Also the results showed that when bioethanol percentage in the mixture increased from zero to 25%, the average amount of UHC, CO2, CO and the number of fine and coarse particles decreased 104.53%, 3.45%, 34.57%, 41.42% and 96.09%, respectively, while the amount of NOX and fuel consumption increased 163.41% and 15.75%, respectively.

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According to the Global Fuel Crisis, it seems necessary to use alternative fuel instead of gasoline. Since the natural gas is cheaper, have higher frequency than gasoline and less pollution, it is a suitable fuel. Many efforts have been done in order to replace gasoline with natural gas. One of the methods is to inject natural gas and gasoline fuel simultaneously and to use the benefits of both fuels. The purpose of this paper is studying natural gas and gasoline blend effect on engine power, torque and emissions. The simulated model was validated in different engine RPMs for gasoline and natural gas, were separately injected into the engine at full load condition. The results of simulation was had good agreement with experiments. The results show that by natural gas and gasoline Simultaneous injection power and torque have been reduced. NOX, HC and CO2 Pollutants change periodically, but their production level is generally lower than gasoline mode, but the CO pollutant increases.

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According to the global air pollution Crisis, it seems necessary to finding a way for cars pollutions. The Combination of alcoholic fuels with gasoline is one of the methods to reduce pollutions. For optimizing engine performance, fuel availability, toxicity and political advantage, a blend of ethanol, methanol and gasoline is likely to be preferable to using any of these individual substances alone. So the purpose of this paper is studying methanol, ethanol and gasoline blend effect on engine emissions at different engine speed. The simulated model was validated in different RPMs of gasoline engine at full load condition. The effect of combined fuel injection in the simulated model was investigated and compared with the experimental results. The results of simulation have good agreement with experiments. The results show that by ethanol and methanol with gasoline blend CO and HC emissions are lower than gasoline mode, but the NOx and CO2 pollutants increases.
 

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