Numerical investigation of the use of different ratios of methanol as fuel in diesel engines

Alcohol fuels are being intensively researched within the scope of efforts to reduce petroleum-based fuel consumption and harmful exhaust emissions in internal combustion diesel engines. Among alcohol fuels, interest in methyl alcohol (methanol) is increasing, especially within the scope of decarbonization of the transportation sector. In this study, it is aimed to numerically investigate the use of different amounts of methanol as an alternative fuel in a diesel engine. For this purpose, the changes in combustion and exhaust emission characteristics as a result of using methanol added to diesel fuel in gradual proportions as fuel in a single-cylinder and direct injection diesel engine model created in the ANSYS-Forte environment were examined and it was also aimed to determine the maximum methanol ratio. The study was carried out in two stages. First of all, the effect of adding volumetric methanol to diesel fuel was investigated. In this way, up to 40% by volume was added, but combustion did not occur at a sufficient level at this rate. Therefore, engine performance, exhaust emissions and combustion characteristics were numerically examined by using mixture fuels consisting of methanol and diesel fuel (M10, M20 and M30) in the ratios of 10%, 20% and 30% by volume. Then, different injection advances were studied with a fuel mixture containing 10% methanol (M10). According to the results obtained, as the methanol ratio in the fuel increases, a decrease is observed in the indicated pressure, maximum pressure, combustion efficiency, heat release, maximum temperature, in-cylinder pressure, HC, NOx and CO emission values, while a slight increase in thermal efficiency is observed at first, but then the increase in the fuel mixture decreases. It was observed that there was a decrease in thermal efficiency due to the increase in methanol ratio. By increasing the injection advance in M10 fuel, which is the second stage of the study, an increase in maximum pressure, combustion efficiency, unburned HC emission, NOx, heat release rate, maximum temperature and in-cylinder pressure values; It was determined that there was a decrease in indicated pressure, thermal efficiency and CO emission as the advance was increased.