Abstract: A numerical study of spray performance in a bipropellant coaxial centrifugal injector is proposed by using the large eddy simulation (LES) method, based on the multiphase volume fraction model of the gas and liquid. The results show that the spray velocity ejected from the inner flow passage is larger than the outer flow passage, and the spray angle increases slightly when both of the two flow passages simultaneously inject. The spray velocity and flow coefficient increase with the decrease of the injector exit length and increase of the injector pressure drop. The spray droplet size (SMD) decreases and the spray angle increases with the increases of the injector pressure drop.

Key words: coaxial centrifugal injector, multiphase fraction model, large eddy simulation(LES), numerical study, spray droplet size, spray angle