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

To evaluate directly gas entrainment (GE) phenomena in fast breeder reactors, we have been studied a numerical simulation method based on a high-precision volume-of-fluid methodology. We have been employed unstructured meshes because exact modeling of complicated geometries in each domain is a key to simulate GE phenomena accurately. Therefore, formulations of each calculation procedure in the high-precision VOF methodology on unstructured meshes are conducted in this paper. Then, unphysical behaviors of velocity distributions near gas-liquid interface induced by inappropriate formulation of pressure gradient are discussed and an appropriate formulation is derived. Finally, the basic GE experiment is simulated using our numerical simulation method. The simulation results shows that the GE phenomena occurs in the same mechanism with the experimental results.