Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 93Citation - Scopus: 6Natural Gas Fueled Compression Ignition Engine Performance and Emissions Maps With Diesel and Rme Pilot Fuels(Elsevier Ltd, 2014) Imran, Shahid Mohammed; Emberson, David Robert; Díez, Alvaro; Wen, Dongsheng; Crookes, Roy James; Korakianitis, Theodosios P.When natural gas is port/manifold injected into a compression ignition engine, the mixture of air and the natural gas is compressed during the compression stroke of the engine. Due to the difference in the values of specific heat capacity ratio between air and natural gas, the temperature and pressure at the time of pilot fuel injection are different when compared to a case where only air is compressed. Also, the presence of natural gas affects the peak in-cylinder (adiabatic flame) temperature. This significantly affects the performance as well as emissions characteristics of natural gas based dual fueling in CI engine. Natural gas has been extensively tested in a single cylinder compression ignition engine to obtain performance and emissions maps.Two pilot fuels, diesel and RME, have been used to pilot natural gas combustion. The performance of the two liquid fuels used as pilots has also been assessed and compared. Tests were conducted at 48 different operating conditions (six different speeds and eight different power output conditions for each speed) for single fueling cases. Both the diesel and RME based single fueling cases were used as baselines to compare the natural gas based dual fueling where data was collected at 36 operating conditions (six different speeds and six different power output conditions for each speed). Performance and emissions characteristics were mapped on speed vs brake power plots. The thermal efficiency values of the natural gas dual fueling were lower when compared to the respective pilot fuel based single fueling apart from the highest powers. The effect of engine speed on volumetric efficiency in case of the natural gas based dual fueling was significantly different from what was observed with the single fueling. Contours of specific NO<inf>X</inf> for diesel and RME based single fueling differ significantly when these fuels were used to pilot natural gas combustion. For both of the single fueling cases, maximum specific NO<inf>X</inf> were centered at the intersection of medium speeds and medium powers and they decrease in all directions from this region of maximum values. On the other hand, an opposite trend was observed with dual fueling cases where minimum specific NO<inf>X</inf> were observed at the center of the map and they increase in all direction from this region of minimum NO<inf>X</inf>. RME piloted specific NO<inf>X</inf> at the highest speeds were the only exception to this trend. Higher specific HC and lower specific CO<inf>2</inf> emissions were observed in case of natural gas based dual fueling. The emissions were measured in g/MJ of engine power. © 2021 Elsevier B.V., All rights reserved.Article Citation - WoS: 11Citation - Scopus: 13Experimental and Artificial Neural Network Modeling Study on Soot Formation in Premixed Hydrocarbon Flames(Elsevier Ltd., 2003) İnal, Fikret; Tayfur, Gökmen; Melton, Tyler R.; Senkan, Selim M.The formation of soot in premixed flames of methane, ethane, propane, and butane was studied at three different equivalence ratios. Soot particle sizes, number densities, and volume fractions were determined using classical light scattering measurement techniques. The experimental data revealed that the soot properties were sensitive to the fuel type and combustion parameter equivalence ratio. Increase in equivalence ratio increased the amount of soot formed for each fuel. In addition, methane flames showed larger particle diameters at higher distances above the burner surface and propane, ethane, and butane flames came after the methane flames, respectively. Three-layer, feed-forward type artificial neural networks having seven input neurons, one output neuron, and five hidden neurons for soot particle diameter predictions and seven hidden neurons for volume fraction predictions were used to model the soot properties. The network could not be trained and tested with sufficient accuracy to predict the number density due to a large data range and greater uncertainty in determination of this parameter. The number of complete data set used in the model was 156. There was a good agreement between the experimental and predicted values, and neural networks performed better when predicting output parameters (i.e. soot particle diameters and volume fractions) within the limits of the training data.Article Citation - WoS: 87Citation - Scopus: 110Effects of Oxygenate Additives on Polycyclic Aromatic Hydrocarbons (pahs) and Soot Formation(Taylor and Francis Ltd., 2002) İnal, Fikret; Senkan, Selim M.Effects of three oxygenate additives (methanol, ethanol, and MTBE) on the formation of polycyclic aromatic hydrocarbons (PAHs) and soot in laminar, premixed, atmospheric pressure, fuel-rich flames of n-heptane were studied at an equivalence ratio of 2.10. A heated quartz microprobe coupled to online gas chromatography/mass spectrometry was used to establish the identities and absolute concentrations of major, minor, and trace species by the direct analysis of samples withdrawn from the flames. Benzene was the most abundant aromatic compound identified. The largest PAH detected was the family of C18H10 (molecular weight of 226) that includes cyclopenta[cd]pyrene and benzo[ghi]fluoranthene. Soot particle diameters, number densities, and volume fractions were determined using classical light scattering and extinction measurements. All the oxygenate additives studied reduced the mole fractions of aromatic and PAH species, as well as soot formation. However, the reduction in soot formation was comparable for different oxygenates under the experimental conditions investigated.