CFD Simulation of Counter-current Two-phase Flow in a Model of PWR Hot Leg

This paper provides a numerical study of the phenomena around the counter-current flow limitation (CCFL) of air-water and steam-water in a model of the hot leg pressurized water reactor (PWR). The calculations were conducted using the commercial CFD software, CFX 13.0 (ANSYS CFX), based on the finite volume method for an Euler-Euler model or free surface model. The simulations were carried out in fully transient manner using a gas/liquid inhomogeneous multiphase flow model coupled with a shear stress transport (SST) turbulence model. In the present numerical study, the drag coefficient was approach by using the Algebraic Interfacial Area Density (AIAD). Next, an image processing technique was also developed in order to obtain the liquid film thickness data in a model PWR hot leg from the high-speed video observations. The results indicated that quantitative agreement between calculation and experimental data was obtained for the occurrence of flooding point and water level inside the hot leg channel.