%0 Journal Article %A Jang, Changsoo S. %A Kim, Sung-Soo %A Choi, Sangmin %D 2000 %I Begell House %N 2 %P 19 %R 10.1615/AtomizSpr.v10.i2.60 %T AN EXPERIMENTAL AND ANALYTICAL STUDY OF THE SPRAY CHARACTERISTICS OF AN INTERMITTENT AIR-ASSISTED FUEL INJECTOR %U https://www.dl.begellhouse.com/journals/6a7c7e10642258cc,3840fa8a1082a05e,7bbc2fa60a85be54.html %V 10 %X Spray characteristics of an intermittent air-assisted fuel injector (AAFI) for a four-stroke gasoline direct-injection engine were investigated using a photographic imaging system. The spatial spray structures were acquired in terms of Sauter mean diameter (D32) and liquid mass concentration. Air entrainment motion was observed just below the poppet valve. Influence of parameters such as ambient air density, supply pressure, and injected air-liquid mass ratio (ALR) was examined. D32 varied from 9 to 30 μm throughout all experimental conditions. The result exhibited a similar tendency to those from diesel injectors in spray tip penetration and atomization characteristics. An intermittent injection caused temporally nonuniform ALR through an injection period. Introducing a set of plausible assumptions, the influence of instantaneous ALR (IALR) on temporary atomization quality was assessed. It showed a comparable trend with that of ALR on D32 of overall spray. The best-fitting curve for drop size distributions of sprays from the AAFI appeared to be a log-Boltzman function. A simple analytical modeling was introduced for predicting mean drop diameters of the AAFI with respect to various operating parameters considered in this study. The model-based equation was found to fit experimental data with an error range comparable to the empirical correlation. %8 2000-04-01