Spray Characteristics of Recessed Gas-Liquid Coaxial Swirl Injector

The effect of recess length on the internal flow development and spray characteristics of a gas-liquid-swirl coaxial injector was investigated both theoretically and experimentally. Three different flow patterns were identified and explored as a function of the recess length. The spray-field dynamics and droplet-size distribution were measured by means of a high-speed photographic technique. An improved theoretical model was established to correlate experimental observations. An expression of the optimal recess length for atomization was obtained.