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The paper discusses the issues of the influence of the fuel spray formation on the generation of self-ignition spots and the development of pre-flame processes in the cylinder of a model diesel engine. The investigations were carried out for a standard diesel fuel and two other types of fuel that were mixtures of ethanol, butanol, and diethylether in a variety of proportions. By applying optical methods of analysis, the authors determined the geometrical indexes of the injected fuel spray as well as fuel mass distribution in the longitudinal and transverse cross section of the fuel spray during the injection process. The location and number of the self-ignition spots in the combustion chamber were evaluated on the basis of a comparison under various conditions: in presence of the charge swirl and at the lack of it. Research conducted for the single-cylinder engine confirmed the possibility of the use of diesel-like fuels for compression ignition engines.
相似文献The preliminary studies on thermal behavior of differently aged natural resins from Russia (Khatanga), Dominican Republic (El Valle), Colombia and Poland (Jantar) were performed. Thermal stability and behavior under elevated temperature were investigated by thermogravimetry (TG) and differential scanning calorimetry (DSC), while the differences in the structure and composition by FT-IR spectroscopy. Analyzed resins show different thermal effects during heating suggesting that possible post-reactions and structural changes occurred. TG results indicated that Dominican, Russian and Colombian resins present relatively high thermal stability under air conditions in the range of 228–300 °C, whereas the mass loss of 5mass% at about 217 °C was observed for Baltic amber. During DSC experiments, the analyzed resins expose thermal events which make impossible determination of glass transition temperature in a raw sample. The results indicate that both TG and DSC cannot be considered as methods for age dating of natural resins and more advanced techniques should be applied. Careful analysis of FT-IR data in the carbonyl region may provide additional information about the composition and history of the natural resin.
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