Orifice Cavitation and Its Effect on Spray Mixing

Abstract

Cavitation characteristics were determined for sharp-edged orifices. Both circular and rectangular orifices were studied. A simple model is proposed, which was experimentally verified over a range in back pressure, L/d, and entrance radius. Sharp-edge orifices were then incorporated into unlike-impinging-doublet injector elements. The spray mixing uniformity was determined at cavitated and noncavitated conditions. Cavitation was shown to result in a substantial reduction in mixing uniformity for circular orifice elements. Over an identical range in experimental conditions, the rectangular orifice element did not experience lowered mixing uniformity. The orifice cavitation and mixing results should find use in a wide range of applications.