Experimental study on spray characteristics of RP-3 kerosene under the near critical condition with different injection conditions

In an aero-engine, the effect of oil-gas mixing directly affects the working condition of the combustion chamber, and the mixing process of RP-3 kerosene near the near-critical point is more complicated because its physical properties are more strongly affected by its own temperature and pressure changes. The injection process of RP-3 kerosene near the near-critical point was photographed under different injection conditions using high-speed ripple shadowing technology. It was found that the increase in air injection pressure and the distance from the nozzle outlet to the cyclone outlet would reduce the jet expansion angle and jet width. The former would reduce the jet's self-excited oscillation frequency, and the latter would increase it.