Study on atomization performance of multi-orifice air-assisted plain jet atomizers

Abstract In this study, the atomization characteristics of several multi-orifice air-assisted plain jet atomizers are investigated. By multiple experimental ways, fuel flow distribution, spray angle and the Sauter mean diameter (SMD) distribution are obtained. Several simulation works are also conducted, showing the internal flow field of the atomizer that can explain the experimental results. The results proved the efficiency of the atomizers, the SMD can be as low as 40 µm and a 25*15 mm well-atomized zone is found on each side of the atomizer. Increasing the inlet air velocity will widen the spray, causing the spray angle to increase from 36.1° for V = 40 m/s to 46.6° for V = 70 m/s. Meanwhile the droplets' diameter are decreased, the SMD range at line Y = 5 mm decreased from 55 to 80 µm to 33–55 µm downstream one of the tested atomizers. The structural parameter influences the spray characteristics by altering the atomizers' internal flow field. The air–fuel mixture tends to concentrate at the rear part of the distributing pipe for larger orifices, causing the peak point of the fuel flux curve to change from X = 39 mm for 2 mm orifice diameter to X = 43.3 mm for 4 mm orifice diameter. These studies will establish an overall view of the atomizers' atomization performance and lay the foundation for the further application of multi-orifice atomizers.