Experimental investigation on the impact of air flow rates and back pressures on kerosene microscopic spray characteristics discharged from an air-assisted pressure-swirl atomizer

Abstract

The air-assisted pressure swirl atomizer has attracted considerable interest owing to its exceptional capacity to generate fine droplets and precisely regulate spray characteristics. The primary objective of the study was to investigate the impact of auxiliary air flow rate, orifice diameter, and ambient back pressure on the kerosene spray cone angle, droplet size and distribution. The results indicate that employing a nozzle with a smaller orifice size leads to a larger spray cone angle. The spray cone angles of the other two orifice sizes exhibit an increasing trend as the auxiliary air flow rate increases. Also, increasing the auxiliary air flow rate effectively reduces the Sauter Mean Diameter (SMD). Additionally, as the auxiliary air flow rate gradually increases, the peak of the particle size distribution shifts towards smaller diameters. Furthermore, as the environmental back pressure increases, there is a noticeable decrease in the SMD. With an increase in ambient backpressure, there is a consistent shift of the peak particle size towards smaller diameters. At an elevated ambient pressure of 1.4 MPa, an increase in the axial distance from the nozzle results in a decrease in the volume percentage of the peak diameter, while simultaneously causing the particle size distribution range to broaden.