Abstract
The study of the effect of blockage on two-phase flow parameters in rod bundle is of significance to the prediction of the thermal-hydraulic behavior of fuel assembly under hypothetical accident conditions. The two-phase flow computational fluid dynamics method was used to simulate the fluid flow phenomenon in 5 × 5 under no- and total sub-channel blockage conditions. The effect of the blockage on the void fraction is most significant in the sub-channel where it is located and the adjacent sub-channels. The effect of the blockage on other flow parameters extends as far as 46 Dh downstream of the blockage. There is an increase in the void fraction after the blockage as a result of bubble coalescence in the region. The effect of these different blockage conditions can provide a reference for the parameter setting of the sub-channel analysis codes.
