Study on applicability of numerical simulation to evaluation of gas entrainment from free surface

Ito, Kei; Sakai, Takaaki; Ohshima, Hiroyuki

An onset condition of gas entrainment (GE) due to free surface vortex has been studied to establish a high coolant velocity fast breeder reactor. In this research, to evaluate the applicability of the numerical simulation to the GE phenomena, numerical simulations were conducted on the basic experimental apparatus of the GE. As a result, traveling behavior of free surface dent, frequency of vortex generation and vortex growing behavior were accurately simulated, although the GE itself was not completely reproduced due to a lack of enough grid partition. In addition, several parameters, such as a free surface level and suction velocity, were numerically examined to evaluate their influence on the GE. The tendencies that lower free surface level or larger suction velocity enhance occurrence of the GE could be simulated. These simulation results implied that the numerical simulation method is enough applicable to the evaluation of the GE.