Numerical simulation was carried out on the atomization process of unlike-doublet impinging jets injector based on the CLSVOF (coupled level-set and volume of fluid) method. The simulation results were compared with the experiment results

and the effect of momentum ratios on liquid sheet characteristics was investigated in detail. The results show that:(1) The CLSVOF method can efficiently capture the liquid sheet characteristics formed by jet impact. The calculated liquid sheet agrees well with the experiment result. (2) In the impinging process of jets

part of the jet flow of large diameter nozzle is not involved in the impact

while the velocity of liquid in the central position drops rapidly after impact

and at the same time

the surrounding liquid maintains the velocity before impact

which results in the formation of cured liquid sheet. (3) Under the conditions of different momentum ratios

the resultant angle in the axis position after impact mainly depends on the momentum ratio of impinging jets. The simulation results are in good agreement with the theoretical calculation results

with the errors less than 10%.