A Numerical Study on the Two-Phase Natural Circulation Flow in Reactor Cavity under External Vessel Cooling

원자로 외벽냉각시 원자로공동에서의 자연순환 이상유동에 대한 수치적 연구

This work presents a numerical analysis of two-phase natural circulation flow in reactor cavity under external vessel cooling. Steady, incompressible, three-dimensional Reynolds-averaged Navier-Stokes equations for multiphase flows with zero equation turbulence model are solved to predict the shear key effect on the circulation rate of cooling water and the distribution of void fraction according to the different mass flow of inlet air. Results show that shear key has a positive effect on the circulation rate of cooling water and induce a local increase of void fraction below the shear key, but not remarkably.