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The presence of cavitation and turbulence in a diesel injector nozzle has significant effects on the subsequent spray characteristics. The influence of nozzle hole shape on internal flow and near-nozzle region fuel injection and atomization under stationary conditions was studied. Five standard-sac nozzles with the same hole inlet diameter but different hole shapes (cylindrical, divergent, convergent, divergent—convergent and convergent—divergent) were used for the investigation of influence of nozzle hole shape on internal flow and spray. Large eddy simulation (LES) along with a two phase homogenous mixture model were employed. From research results, three important conclusions can be drawn. Firstly, the geometry characteristics of the orifice had a great impact on internal flow of injection nozzle. The cavitation can raise the effective velocity at the nozzle exit and strengthen flow disturbance of the nozzles, and such effect became even more obvious with higher injection pressure, e.g., 100MPa. Secondly, the diverging-shaped nozzle was more prone to cavitate, that’s the very opposite of the converging nozzles. Stronger outlet cavitation intensity was found in hyperbolic-shaped nozzles, and stronger inlet cavitation intensity was found in elliptic-shaped nozzles. Thirdly, the cavitation intensity had a great impact on the near-nozzle region fuel break-up and atomization, especially the outlet cavitation such as the diverging-shaped nozzle and hyperbolic-shaped nozzle under the condition of high injection pressure, which were beneficial to the performance of diesel engine, the fuel injection and atomization.