Flow rate and spray characteristics of gas centered swirl gas-liquid coaxial injector

To study the flow rate and spray characteristics of the gas-liquid recess coaxial injector, which consists of the gas-centered orifice injector and the liquid swirl injector, High-speed Photography Technique and Phase Doppler Particle Analyzer (PDPA) were used. At?normal temperature and pressure, the flux?is proportional to the pressure drop to the power of 0.477 nearly. The spray field is a hollow cone with a fixed spray angle, approximately, 110°. The spray angle becomes bigger with the pressure drop of the liquid propellant bigger. In the case of the fixed pressure drop of the liquid propellant, the spray angle is affected by the gas and it declines due to the entrainment. The breakup length is related to the spray angle and it decreases when the angle increases and vice versa. In the case of fixed axial length away from the outlet of the injector, the axial and radial speed of the particles decline while the radial length rises. Additionally, with the radial length increasing, the Sauter Mean Diameter becomes bigger, followed by little decrease. The distribution shape of SMD along the radial direction has two peaks, as a saddle. In the case of the fixed radial length, the axial speed and SMD go down when the axial length goes up.