Unsteady natural convection in a cylindrical containment vessel (CIGMA) with external wall cooling; Numerical CFD simulation

外面冷却時の格納容器内非定常自然対流; CFDシミュレーション

Hamdani, A.  ; 安部 諭  ; 石垣 将宏 ; 柴本 泰照 ; 与能本 泰介 

Hamdani, A.; Abe, Satoshi; Ishigaki, Masahiro; Shibamoto, Yasuteru; Yonomoto, Taisuke

In the case of a severe accident, natural convection plays an important role in the atmosphere mixing of nuclear reactor containments. In this case, the natural convection might not in the steady-state condition. Hence, instead of steady-state simulation, the transient simulation should be performed to understand natural convection in the accident scenario within a nuclear reactor containment. The present study, therefore, was aimed at the transient 3-D numerical simulations of natural convection of air around a cylindrical containment with unsteady thermal boundary conditions (BCs) at the vessel wall. For this purpose, the experiment series was done in the CIGMA facility at Japan Atomic Energy Agency (JAEA). A 3-D model was simulated with OpenFOAM, applying the unsteady Reynolds-averaged Navier-Stokes equations (URANS) model. Different turbulence models were studied, such as the standard k-, standard k-, k- shear stress transport (SST), and low-Reynolds-k- Launder-Sharma. The results of the four turbulence models were compared versus the results of experimental data.