Two-phase flow simulation of gas entrainment phenomena in large-scale fast reactor

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

The authors have been developed a high-precision numerical simulation algorithm for gas-liquid two-phase flows to simulate the gas entrainment (GE) phenomena in a large-sized sodium-cooled fast reactor in Japan (JSFR). In this paper, the developed simulation algorithm is applied to the GE phenomena in a large-scale water experiment which models the complicated geometrical configurations of the system components in JSFR. For the numerical simulation, an unstructured mesh with about one million cells are generated and optimized to simulate the interfacial deformations near inlet and outlet pipes which cause vortical flows behind them to induce the GE phenomena. As a result of the unsteady simulation, a typical interfacial dynamic behavior, i.e. the development of a gas core (interfacial dent), is well simulated. Therefore, it is confirmed that the developed simulation algorithm is suitable to evaluate numerically the GE phenomena in JSFR.