THE SPRAY CHARACTERISTICS OF SWIRL AND SLIT INJECTOR USED TO DISI ENGINE USING LIEF AND MIE-SCATTERING METHOD

Abstract

The spray characteristics of DISI injector has a great role in engine efficiency and emission. Thus, many researchers have studied to investigate the spray characteristics of swirl and slit injectors that are used in DISI engine. In this study, we tried to provide spray parameters, which effected on the spray characteristics such as injection pressure, ambient pressure and ambient temperature. In addition, we calculated b t and c t to investigate the break up mechanism of test injectors. The laser-induced exciplex fluorescence (LIEF) technique, which based on spectrally resolved two-color fluorescent emissions, has applied to measure the images of liquid and vapor phase separately. In this study, the TMPD/naphthalene has used as the additive proposed by Melton to detect the LIEF signal. In the LIEF technique, the vapor phase has detected by the monomer fluorescence while the liquid phase has tracked by the exciplex fluorescence. From this experiment, we found that the spray area of the vapor phase has increased with elapsed time after injection and the area of liquid has decreased when the ambient pressure is 0.1MPa. However, the area tends to increase until the end of injection when the ambient pressure is 1.0MPa.