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The authors are conducting tests of a newly devised rapidly operating secondary actuator (ROSA) aimed at providing controllable multiple injection. An injection test cell has been constructed. Two test setups are available for both diesel spray visualization and flow rate measurements. Up to six shots per cycle were implemented. A high-speed digital camera was used to have accurate data regarding spray dynamics. Processed data are obtained for liquid jet tip velocity, injection shots duration, and their delay with regard to electric setup. The stability of phasing lies within 50 μs. The shortest injection shot duration is 74 μs, maximum variability of duration is 50 μs.

Internal flow characteristics of a close coupled catalytic converter were examined by LDV measurements and high speed flow visualization. Although previous studies have been done on catalytic converters, they were conducted at steady state and using water flow seeded with a small quantity of tracer particles. The purpose of this study was to develop a better understanding of dynamic flows inside catalytic converters. The high speed flow visualization films and LDV results showed that areas of separation and circulation were present in the inlet region of the converter. Backflows into the neck of the converter were also observed. Each cylinder exhausted into a different region of the converter, with the front-middle region having the heaviest amount of flow. Large bursts of flow were created by each cylinder, while other regions of the inlet region showed backflows or very low flow rates. The midsection of the converter had a more uniform overall flow pattern.

This paper reports the development of vapor/liquid visualization systems based on an exciplex (excited state complex) formed between dimethyl- or diethyl-substituted aniline and trimethyl-substituted naphthalenes. Quantum yields of individual monomers were measured and the exciplex emission spectra as well as fluorescence quenching mechanisms were analyzed. Among the many systems and formulations investigated in this study, an exciplex consisting of 7% 1,4,6-trimethylnaphthalene (TMN) and 5% N,N-dimethylaniline (DMA) in 88% isooctane was found to be the best system for the laser-induced exciplex fluorescence (LIEF) technique, which is used to observe mixture formation in diesel or spark ignition (SI) engines. Observation of spectrally separated fluorescence from monomer in the gas phase and from exciplex in the gasoline fuel [1] requires that the exciplex forming dopants have boiling points within the distillation range of gasoline (20 to 215°C).