Effect of ambient pressure on the performance of a gas-centered swirl coaxial injector

In this study, water and air were used as simulated media to investigate the spray characteristics of a gas-centered swirl coaxial (GCSC) injector under different ambient pressures through experimental, simulation, theoretical approaches. The results showed that for same liquid mass flow rate, breakup length film decreased with increasing pressure, extent decrease diminishing pressure increased. addition, it was found larger shorter length. Moreover, any gas–liquid ratio (GLR), angle increased significantly suddenly expanded compared no-ambient condition. At time, As increased, while decreased. When GLR small, self-pulsation occurred, which gradually disappeared pressure. frequency periodic result combined effects centrifugal force rotating film, surface tension aerodynamic force, difference inside outside film. Overall, these findings provide insight into GCSC injectors pressures, can be importance design optimization rocket engines.