Background: For the nuclear power plant

the flow resistance of steam generator primary nozzles is an important part of the primary flow resistance. Consequently

the study on the calculation method of the flow resistance and that on its main influence factor are of great significance to the design of the nuclear power plant. In engineering

the k-ε models

including Standard k-ε model

RNG k-ε model and Realizable k-ε model

are widely applied to the simulation of flow field. Purpose: We aim to make sure which of these k-ε models is the most appropriate to calculate the flow resistance of steam generator primary nozzles. And the influence of the chamfer on the flow resistance was studied. Methods: First of all

the k-ε models mentioned above were respectively used to simulate the flow field and calculate the flow resistance. The applicabilities of Standard k-ε model

RNG k-ε model and Realizable k-ε model were discussed via comparing the numerical results with those of the experiment. Then

the most appropriate model was adopted to study the influence of the chamfer on the flow resistance. Results: Compared with other k-ε models

Realizable k-ε model was the most appropriate one for the calculation of the flow resistance of steam generator primary nozzles. The chamfer was helpful for reducing the flow resistance

especially for the outlet nozzle. Conclusion: Numerical modeling can be used to determine an appropriate computing method for flow resistance of steam generator primary nozzles

and study the main influence factor on the flow resistance. This work may have certain reference value to the design of steam generators and the computation for flow resistance of other equipment in the nuclear power plant.