Abstract In order to study influences of tongue fillet radius on flow characteristics of annular casing in a reactor coolant pump, 11 annular casings were designed with various tongue fillet radii for a reactor coolant pump model with 0.4 scaled-down factor. Meanwhile, 10 cross-sections in the annular casings were specified to characterize the flow field for variable fillet radii. The flow fields in the pumps with theses casings were simulated under design condition by using CFD method. The results show that the pressure increases until a peak then decreases along the primary flow direction in the annular casing, the peak is achieved at an 180° circumferential angle measured from the center line of the diffuser along the primary flow. Under the design condition, the hydraulic loss in the annular casing is mainly generated in the first quarter annular fluid region starting from the center line of the diffuser. The fillet radius has a certain impact on pump performance, specially, on the hydraulic performance of the casing, and almost fails to influence on the performance of impeller and guide vane. With increasing fillet radius, the hydraulic loss in the annular casing decreases firstly and then increases, and the minimal loss is reached at a radius <i>R</i>=50 mm. In this case, the hydraulic performance of the casing is the best, and the performance of the pump is optimal. The results can provide a theoretical basis for design of tongue fillet of annular casing.
CHENG Xiao-Rui-1,2,BAO Wen-Rui-1等. Influences of tongue fillet radius on flow characteristic of annular casing in reactor coolant pump[J]. Journal of Drainage and Irrigation Machinery Engin, 2017, 35(9): 737-.