Experimental study on atomization of plane jet injector in high pressure co-axial airflow

An experimental study has been carried out on the effect of high ambient air pressure on the spray characteristics of a plane jet injector in coaxial high-velocity airflow. The air pressures tested range from 1 to 16 atm, the airflow velocity from 60 to 120 m/s, and the pressure drops of the injector tested from 0.2 to 2 MPa, the working fluid is water. The key feature of the experiment is to use a convergent-divergent nozzle to maintain a high air pressure in the test chamber and at the same time to maintain a high airflow velocity in the atomization zone. It totally eliminates air recirculation and the problem of slow droplet settling in a commonly used pressurized vessel for high-pressure atomization. The results show that the Sauter mean diameter decreases monotonically with the increase of ambient air pressure, and at different air velocities the effect of the air pressure is different. The drop size distribution parameter N in the Rasin-Rammler distribution decreases slightly with the increase of ambient air pressure.