Experimental Study and Numerical Simulation on Spray Characteristics of New-Type Air-Assist Nozzle

To investigate the spray characteristics of a new-type air-assist nozzle,three-dimensional laser phase Dopper analyzer（ PDA） was used to measure the spray parameters. The external flow fields of the nozzle were simulated by means of computational fluid dynamics（ CFD）. The distributions of the diameter and the axial velocity for the droplets were analyzed respectively. The results indicate that,the mean diameter of the droplets fluctuates along the center axis. The distance between the measurement point and the nozzle increases,the axial velocity of the droplets decreases. The further the measurement point from the center axis is,the smaller the axial velocity of the droplets is. With the increase of the nozzle pressure drop,the axial velocity of the droplets improves while the mean diameter of the droplets is reduced,and the distribution uniformity of the droplets is better for the diameter. The simulation result agrees well with the experimental data. The average deviation ranges from 3.9% to 7.7%.