Development of a refined k-ε model and its application to stratified sodium flows

In this study, buoyancy effects on turbulent quantities were experimentally investigated in stably stratified water and sodium flows. Turbulence measurements were carried out in water tests with a laser Doppler velocimetry system, and the buoyancy effects on turbulent characteristic quantities were formulated as functions of local Richardson number. In sodium tests, the relationship between turbulent Prandtl number and local Richardson number was evaluated and it was compared with the results of water tests. A two-equational turbulence model was refined with those experimental knowledges and it was applied to the stratified sodium flows to clarify the validation of this model