In order to research the transient spray characteristics of the air-assisted injector and verify the accuracy of the simulation model

the spray characteristics of the air-assisted injector were investigated by CFD simulation and experiment. The CFD simulation had been carried out that the transient injection with different back pressure and inject pressure was simulated. The spray development in the constant volume bomb had visualized by the high speed camera. The SMD of the fuel droplets in the atmospheric environmenthad measured by the laser particles test device. The results show that the high speed compressed air from the injector and the fuel are strongly coupled

and the vortex ring structures come out in the downstream; the increased average rate in experiment by reducing 0.2MPa of back pressure is 3.62 times than increasing 0.2MPa of inject pressure; the average error of average rate between experiment and simulation is 9.94%; the SMD average error of the outlying of injector between experiment and simulation is 4.33%.