Mass-Related Properties of Atomizers for Direct-Injection SI Engines

Mass-related properties of four atomizers were estimated with the use of a mechanical transient patternator. The properties presented on a temporal and spatial basis are the axial liquid mass flux, liquid fuel to air ratio, and liquid axial velocity. The data are presented in two formats. The first format consists of the mass-related properties that occurred radially between two planes positioned 2.0 cm and 2.25 cm along the atomizer axis. A second format consists of interpolated contour plots of the axial liquid mass flux for all of the spray systems studied.

The atomizers used in the study consisted of three liquid-only high-pressure systems and one air-assist system. Two of the liquid-only high-pressure systems and the air - assist system were operated with a volumetric delivery of 20 mm³ per injection while injecting into ambient conditions. A third liquid-only high-pressure system was operated with a delivery of 15 mm³ per injection.

Ranges of 0 to 10 for the liquid fuel to air ratios, and 0 to 40 g/cm²/sec for the mass flux were observed. Average axial velocities were in the range of 0 and 2300 cm/sec. All of the measured properties exhibited large variations in magnitude and location, depending on injection type.