LAUSR

Abstract Scaled-down reactor models are widely used to investigate the reactor integral hydraulic characteristics, due to the feasibility and economy. However, no definite conclusion can be drawn from previous researches for the effects of different scaling methods on simulation results. In this paper, in order to analyze the effects of simulation core design parameters and flow flux on core inlet flow distribution, a CFD simulation is conducted based on the hydraulic tests of the 1/4 scale model of 600 MW reactor in Qinshan phase II. The effects of different scaling velocities, core resistance distributions and lateral resistance on flow distribution are investigated. Calculation results reveal that the uniformity of flow distribution increases with test velocity. Ignoring the resistance of fuel assembly would reduce the uniformity of flow distribution. The flow distributions under conditions of uniformly and segmented distributed core resistance are basically the same, indicating that the detailed simulation of axial pressure drop distribution in assemblies is unnecessary for the design of hydraulic simulator of assembly. The lateral resistance could significantly affect the flow distribution and excessive lateral resistance would reduce the uniformity of distribution.