Experimental Investigation on Spray Characteristics of Pressure-Swirl Atomizers for a Small-Sized Jet Engine

This study investigated characteristics of sprays generated with two geometrically different pressure-swirl atomizers for a small-sized aviation turbine engine using Particle Image Velocimetry (PIV) and Phase-Doppler Anemometry (PDA). The former nozzle is a spill-return type; the latter one is the intended upgrade without the spill return. Single-camera and stereoscopic PIV measurements yield distribution of mean velocity measured in an axial cross section of the spray cone. PDA measurements yield drop-size distribution and axial velocity data. Performed measurements revealed significant differences in spray characteristics of the measured nozzles investigated in the same operating regimes on a cold test bench. These differences are discussed in detail. Analysis of differences between the two nozzles elucidates the possible impact of the nozzle replacement on the combustion process. This study provides an extensive database for validation of numerical models of the tested nozzles.