Electrostatic Fuel Atomization and Spray Dispersal Demonstration.

摘要

The purpose of this work is to characterize charged spray plumes, test the validity of existing spray/plume models, provide a basis for evaluating these plumes for gas turbine fuel and ignitor systems service. Plumes generated by a charge injection atomizer in nitrogen (< or = bar, absolute) have been analyzed using an Aerometrics Phase Doppler Particle Analyzer (PDPA). A 10 bar the outer, small droplet sheath is characterized by a Sauter mean diameter (D32) of about 55 microns, a span of about 0.7 and a number median of about 20 microns. The inner, 'large droplet' core is characterized by D32 about = 110 microns and the same span. These data conform to a predicted overall droplet size distribution exhibiting a polydispersed profile: primary peak at about 105 microns, and secondary peaks at about 85 and 135 microns. The peaks are associated with the core region; the near constant profile below about 85 microns is characteristic of the sheath. Contrary to prediction, D32 increased modestly with pressure in these tests due to two factors: output charge density levels remained fixed with increasing pressure due to shortening of the sprayer caused by droplets stagnating in the test chamber; and, the predictable, lateral plume core expansion to the probe sampling position. A modest air flow over the spray unit corrects these problems. (jhd)