Formulation of high-precision volume-of-fluid method establishing appropriate balance between pressure and surface tension and its application to gas entrainment phenomena in fast breeder reactors

Ito, Kei; Kunugi, Tomoaki*; Ohshima, Hiroyuki; Kawamura, Takumi*

To evaluate directly gas entrainment phenomena in fast reactors, a numerical simulation method based on a high-precision volume-of-fluid (VOF) methodology have been studied. Unstructured meshes to subdivide simulation domains have been employed and formulations of each calculation procedure in the high-precision VOF methodology on unstructured meshes are briefly presented. Calculation procedures of surface tension forces are also presented. In addition, unphysical behaviors of velocity distributions near gas-liquid interface induced by inappropriate formulation of pressure gradient are addressed and an appropriate formulation is presented considering proper balance conditions between pressure and surface tension forces. Finally, the improved simulation method is applied to the basic GE experiment. The simulation results show that the GE phenomena occur in the same mechanism with the experimental results.