RT Journal Article ID 7bbc2fa60a85be54 A1 Jang, Changsoo S. A1 Kim, Sung-Soo A1 Choi, Sangmin T1 AN EXPERIMENTAL AND ANALYTICAL STUDY OF THE SPRAY CHARACTERISTICS OF AN INTERMITTENT AIR-ASSISTED FUEL INJECTOR JF Atomization and Sprays JO AAS YR 2000 FD 2000-04-01 VO 10 IS 2 OP 19 AB 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. PB Begell House LK https://www.dl.begellhouse.com/journals/6a7c7e10642258cc,3840fa8a1082a05e,7bbc2fa60a85be54.html